Differentiation of Pt?Fe and Pt?Ni3 Surface Catalytic Mechanisms towards Contrasting Products in Chemoselective Hydrogenation of α,β-Unsaturated Aldehydes

Article abstract of DOI:10.1002/cctc.202001482

Noble-metal catalysts serve as an irreplaceable role in pharmaceutical, perfume and fine chemicals fields. However, there still remains a grand challenge in controlling chemoselectivity. Herein, we have synthesized a bimetallic nanostructure supported on porous metal-organic frameworks (Pt?Fe/UiO-66, Pt-Ni₃/UiO-66), in which Pt nanoparticles was modified with non-noble metal (Fe or Ni) directly. The as-synthesized catalysts can function as a switch for selective hydrogenation of α,β-unsaturated aldehydes to afford the potential products on-demand. In comparison with the conventional Pt-based catalysts, Pt?Fe/UiO-66 and Pt-Ni₃/UiO-66 catalysts exhibit excellently catalytic activity, enhanced selectivity and improved stability for selectivity hydrogenation. The partial charge reconfiguration and electronic coupling effect existing in such distinctive bicomponent nanocatalysts was confirmed by some comprehensive characterization and density functional theory (DFT) calculations. The developed method for precisely modification the composition and interaction between the noble metal and non-noble metal provides a feasible avenue to design the advanced catalysts.

Full text of DOI:10.1002/cctc.202001482

The European Society Journal for Catalysis
Supported by
Accepted Article
Title: Differentiation of Pt-Fe and Pt-Ni3 Surface Catalytic Mechanisms
toward Contrasting Products in Chemoselective Hydrogenation of
α,β-Unsaturated Aldehydes
Authors: Liangmin Ning, Mingtao Zhang, Shengyun Liao, Yuting
Zhang, Dandan Jia, Yunfang Yan, Wen Gu, and Xin Liu
This manuscript has been accepted after peer review and appears as an
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to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
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content of this Accepted Article.
To be cited as: ChemCatChem 10.1002/cctc.202001482
Link to VoR: https://doi.org/10.1002/cctc.202001482
01/2020

10.1002/cctc.202001482
ChemCatChem
FULL PAPER
Differentiation of Pt-Fe and Pt-Ni3 Surface Catalytic Mechanisms
towards Contrasting Products in Chemoselective Hydrogenation
of α,β-Unsaturated Aldehydes
Liangmin Ning,[a] Mingtao Zhang,[a] Shengyun Liao,[b] Yuting Zhang,[a] Dandan Jia,[a] Yunfang Yan,[a]
Wen Gu,*[a] and Xin Liu*[a]
[a]
Dr. L.-M. Ning, Prof. Dr. M.-T. Zhang, Y.-T. Zhang, D.-D. Jia, Y.-F. Yan, Prof. Dr. W Gu,* Prof. Dr. X. Liu*
College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Tianjin Key Laboratory of Metal and Molecule Based Material
Chemistry, Collaborative Innovation Centre of Chemical Science and Engineering.
Nankai University.
Tianjin, 300071, China.
E-mail: liuxin64@nankai.edu.cn; guwen68@nankai.edu.cn
[b]
Prof. Dr. S.-Y. Liao
Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering.
Tianjin University of Technology.
Tianjin, 300384, China.
Supporting information for this article is given via a link at the end of the document.
the reported reaction systems are not beneficial for selective
transformation.[3] Therefore, improving the efficiency and
selectivity with a certain bond (C=C or C=O) in the SH of α,β-
unsaturated aldehydes to beam the highly value-added
chemicals is challenging and significant.
Abstract: Noble-metal catalysts serve as an irreplaceable role in
pharmaceutical, perfume and fine chemicals fields. However, there
still remains a grand challenge in controlling chemoselectivity.
Herein, we have synthesized a bimetallic nanostructure supported
on porous metal-organic frameworks (Pt-Fe/UiO-66, Pt-Ni3/UiO-66),
in which Pt nanoparticles was modified with non-noble metal (Fe or
Ni) directly. The as-synthesized catalysts can function as a switch for
selective hydrogenation of α,β-unsaturated aldehydes to afford the
potential products on-demand. In comparison with the conventional
Pt-based catalysts, Pt-Fe/UiO-66 and Pt-Ni3/UiO-66 catalysts exhibit
excellently catalytic activity, enhanced selectivity and improved
stability for selectivity hydrogenation. The partial charge
reconfiguration and electronic coupling effect existing in such
distinctive bicomponent nanocatalysts was confirmed by some
comprehensive characterization and Density Functional Theory
(DFT) calculations. The developed method for precisely modification
the composition and interaction between the noble metal and non-
noble metal provides a feasible avenue to design the advanced
catalysts.
Platinum (Pt)-based catalysts have been widely employed
and demonstrated to be the effective catalysts for SH because
of their high activity for H2 dissociation.[4] However, it is difficult to
achieve the satisfactory catalytic properties upon using
unmodified Pt nanoparticles (NPs) as the main active sites.
From a mechanistic point of view, the electronic and geometrical
structures of the catalytic sites determine the adsorption mode
and strength of the substrate.[5] In the catalytic process,
preferentially adsorbing and activating the target functional
group on the catalyst surface is promising but challenging. To
solve this problem, substantial efforts have been made such as
confining Pt NPs in porous materials, downsizing Pt NPs to
clusters, even to single atoms, adding secondary metals or
metal oxides, etc..[6]
Introduction
Selective hydrogenation (SH), an important industrial process,
are widely used in various chemical industry filed. For example,
the main semihydrogenated products such as unsaturated
alcohols (by hydrogenation at C=O bond) and saturated
aldehydes (by hydrogenation at the conjugated C=C bond) from
the α, β-unsaturated aldehydes have been used in
pharmaceutical intermediates, fragrances, perfumes and fine
chemicals areas.[1] A. Mulle et al. reported hydrocinnamaldehyde
Bicomponent catalysts usually exhibit superior catalytic
properties compared with single-component catalysts thanks to
the electronic and geometric modifications.[7] The introduction of
secondary component not only reduces the usage of noble
metal Pt in the synthetic procedure, but also could adjust the Pt
electronic redistribution (e.g., d-band structure) by the ligand and
strain effects.[8] For instance, Pt-Fe (Co, Sn) based bicomponent
catalysts were widely investigated for the SH of α,β-unsaturated
aldehydes/ketones. Therein, the secondary component (FeOx,
CoOx and SnOx) as a Lewis acid are coordinately unsaturated,
which can promote the preferential adsorption and activation of
the C=O bonds.[9] Hosono and coworkers reported the supported
(HCAL)
–
the product of selectively hydrogenation of
cinnamaldehyde is an important intermediate in the treatment of
HIV.[2] At present, it is an extremely challenge to develop high
efficient catalysts for orientation the corresponding products on-
demand, because the thermodynamical and kinetical effects in
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RuFe catalysts showed high catalytic activity and selectivity in
cinnamaldehyde hydrogenation, and confirmed the electron
transfer happen between Ru and Fe. The negatively charged Ru
sites favor the adsorption and polarization of electrophilic C=O
bonds.[10] The aforementioned researches display designing and
manipulating the well-defined bimetallic catalysts has become a
powerful strategy to reveal the origin of synergistic effect.
with the desire to control chemoselectivity. The surface
characterization and Density Functional Theory (DFT)
calculations demonstrate that electron injection from non-noble
3d-transition metal (Fe, Ni) to Pt promotes H2 dissociation on the
electron-rich Pt site, and the electron-deficient Fe and Ni
preferentially adsorb and active C=O group and C=C group of
the CAL, respectively, to obtain the industrially desirable product.
Metal-organic frameworks (MOFs), as a special class of
porous materials, have been emerging as the attractive
materials in the catalytic field owing to their well-defined
structure, ultra-high surface area, flexible tailorability and
accurate designability, all of which cater to the catalytic
requirement well.[11] Zirconium-organic frameworks (UiO-66)
have been widely applied because the textural (Lewis acidity)
and structure (high surface area) performance of UiO-66 are
beneficial for the interaction between the metal sites and
support.[12] Our group has lately carried out some work to
explore the oxidative transformation of furfural over Au NPs
supported functionalized UiO-66-X (X = NH2, COOH, NO2) and
some good results has been obtaied.[13]
Results and Discussion
A series of UiO-66 anchored Pt-Fe or Pt-Ni bicomponent
nanocatalysts with certain atom ratios were prepared by a
convenient method using chloroplatinic acid (H2PtCl6·6H2O),
nickel(II) chloride hexahydrate (NiCl2∙6H2O), and iron(III) chloride
hexahydrate (FeCl3∙6H2O) as the metal precursors, sodium
borohydride (NaBH4) as the reducing agent, poly-
(vinylpyrrolidone) (PVP) as a stabilizer and deionized water as
the component solvent (see the Experimental Section for details).
The as-obtained Pt-based (Pt-Fe/UiO-66, Pt-Ni3/UiO-66)
bimetallic catalysts were characterized by High-Resolution
Transmission Electron Microscopy (HRTEM) and High-
Resolution Scanning Electron Microscopy (HRSEM). As
illustrated in Figure 1a and 1d, the prepared Pt-Fe/UiO-66 and
Pt-Ni3/UiO-66 retained the octahedral structure morphology of
the original UiO-66. As detected by HRTEM in Figure 1c and 1f,
In this work, we used the secondary component (Fe or Ni)
to decorate the noble metal Pt and MOFs as supporter to
fabricate Pt-Fe/UiO-66 and Pt-Ni3/UiO-6 catalysts. The SH of
cinnamaldehyde (CAL) containing both C=C and C=O bonds
was selected as a typical model reaction for investigation the
performance of the Pt-Fe(Ni3)/UiO-66 bi-component structure
Figure 1. HRSEM and HRTEM images of as-obtained (a-c) Pt-Fe/UiO-66 and (d-f) Pt-Ni3/UiO-66 with interplanar distances; HRTEM-EDX images and elemental
mapping for (g, h) Pt-Fe/UiO-66 and (i, j) Pt-Ni3/UiO-66 (Note: The Cu-Kα and Cu-Kβ were come from copper mesh which were used as support in measurement).
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the well-resolved lattice fringes with interplanar spacings of
0.223 nm and 0.212 nm can be indexed to the (111) plane of Pt-
Fe phases and Pt-Ni3 phases, respectively.[7d,14] The resulting
HRTEM-EDX mapping images and CO pulse chemisorption
clearly indicate that Pt-Fe and Pt-Ni3 nanostructures should be
highly dispersed on the surface of UiO-66 (Figure 1g, 1i and S1).
Besides, HRTEM-EDX spectrum of Pt-Fe/UiO-66 and Pt-
Ni3/UiO-66, showed the atomic ratio of about Pt:Fe = 53.8:46.2
(1:1) and Pt:Ni = 23.1:76.9 (1:3), respectively (Figure 1h and 2j).
Moreover, the FT-IR spectra of UiO-66, fresh Pt-
Fe(Ni3)/UiO-66, and used Pt-Fe(Ni3)/UiO-66 also verified the
chemical integrity of zirconium-organic frameworks under the
established preparation and catalytic conditions (Figure 2d). In
addition, the XRD patterns of the as-obtained catalysts are
provided in Figure 2e. The crystal structure of the UiO-66 did not
change before and after Pt-Fe and Pt-Ni3 were supported, and
the well-defined characteristic peaks attributed to the diffraction
patterns of UiO-66 phase. It is worth noting that the
characteristic diffraction peaks of platinum species do not
appear due to low metal loading (ca. 0.75wt %, measured by
ICP-AES). The surface acid sites of the synthesized catalysts
were analyzed by in situ pyridine-adsorption DRIFTS (Figure 2a
and S2). According to the literature, the bands at about 1439
cm−1 and 1605 cm−1 were assigned to Lewis acid sites, and the
band at around 1578 cm−1 was assigned to Brønsted acid sites.
Meanwhile, the feature at about 1485 cm−1 was attributed to
either or both Lewis and Brønsted acid sites.[14] The coexistence
of Lewis and Brønsted acid can be attributed to MOFs because
UiO-66 has abundant metal nodes (Lewis acid sites) and
uncoordinated carboxylic ligands (Brønsted acid sites). The
Lewis acid sites of the UiO-66 are beneficial for the interaction
between the metal species and supports.[12]
Furthermore, to further identify the surface electronic states
of Pt-based catalysts, the representative samples were
evaluated by in situ DRIFTS with a CO probe molecule. Figure
2b shows the DRIFTS spectra of CO-adsorbed on catalysts after
purging with nitrogen at 25 ℃ for 10 min. The strong broad CO-
adsorption band at about 2050 cm−1 is assigned to the vibration
frequency of CO interacting with Lewis acid sites in the MOFs.[15]
In addition, one stable band (around 2085 cm-1) can be assigned
to CO linearly adsorbed on Pt sites were detected on
synthesized Pt-based catalysts. The CO band position of Pt-
Fe(Ni3)/UiO-66 is a little lower than that observed on Pt/UiO-66
catalysts, which means that the relatively strong interaction
between Pt and Fe or Ni occurred in the synthetic process.[14,16]
The X-ray Photoelectron Spectroscopy (XPS) was employed to
investigate the chemical state of the Pt/UiO-66, Pt-Fe/UiO-66
and Pt-Ni3/UiO-66 (Figure 2c). The binding energy of Pt 4f7/2
peak at 71.86 eV corresponds to Pt0 species.[4] It can be seen
that the Pt 4f region of Pt-Ni3/UiO-66 and Pt-Fe/UiO-66 catalysts
show significant shifts to lower binding energies of 0.60 and 0.31
eV, respectively, when compared with single-component Pt/UiO-
66 catalyst, indicating that the electron transfer from Fe or Ni to
Pt.[7a] To further reveal the iron and nickel chemical states, the
deconvolution results for Fe 2p and Ni 2p were evaluated in
Figure S3. The Fe 2p3/2 peaks at 710.2 and 711.8 eV can be
corresponded to Fe2+ and Fe3+ species, respectively, and the Ni
2p3/2 peaks at 855.6 eV can be attributed to Ni2+.[14] Briefly, the
charge accumulation and chemical bonding leads to the obvious
shift of characteristic peaks, which indicats that the interaction
between
Pt
species
and
Fe
or
Ni
species.
Figure 2. In situ DRIFT spectra of (a) pyridine-adsorption and (b) CO-adsorption on UiO-66 and Pt-based catalysts after purging with N2; (c) XPS Pt 4f spectra of
synthesized Pt-based catalysts; (d) FT-IR spectra and (e) XRD patterns of UiO-66, Pt-Fe/UiO-66, used Pt-Fe/UiO-66, Pt-Ni3/UiO-66, used Pt-Ni3/UiO-66.
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However, for Pt-Ni3 phase interface system, the degree of
electron localization of Pt atoms changes slightly. Therefore, the
degree of electron localization and chemical bonding of Pt atoms
also reveal the interaction for Pt-Fe system is stronger than that
of the Pt-Ni3 system.
The catalytic properties of the as-obtained Pt-Fe/UiO-66
and Pt-Ni3/UiO-66 were evaluated in SH of α,β-unsaturated
aldehydes. The hydrogenation scheme of cinnamaldehyde
(CAL) is given as Figure 4a, where the generated products
include cinnamic alcohol (COL), phenylpropanol (HCOL),
phenylpropanal (HCAL) and so on. For the Fe/UiO-66 and
Ni/UiO-66 catalytic systems, the main chemoselectivity were
COL (85.4%) and HCAL (76.6%), respectively (Figure 4b),
however, the original UiO-66 showed lower activity. With the
introduction of Pt species, the catalytic activity has been greatly
improved, but the selectivity of the product was aimless. Notably,
when Pt-Fe/UiO-66 was used as the catalyst, the conversion of
CAL and the selectivity of COL were 87.4% and 96.2%,
respectively. In addition, a 58.6% conversion of CAL and 86.1%
selectivity of COL were obtained when Pt-Ni/UiO-66 was
employed. Then, we have prepared Pt-Co/UiO-66, Pt-Co3/UiO-
66, Pt-Sn/UiO-66, and Pt-Sn3/UiO-66 catalysts for the selective
hydrogenation of CAL. As shown in Table S2, the Pt-Co/UiO-66
and Pt-Sn/UiO-66 show high selectivity for COL. It is
unsatisfactory that Pt-Co3/UiO-66 and Pt-Sn3/UiO-66 do not
obtain high HCAL selectivity. These results indicated that the
combination of Pt and Fe/Ni is desirable for the chemoselective
transformation of CAL to COL or HCAL in the presence of
molecular hydrogen on-demand.
Figure 3. (a, b) Crystalline phase structures, (c, d) density of states and (e, f)
ELF contour plots on the (111) plane of Pt-Fe and Pt-Ni3 surfaces.
The different planes of catalysts have
a noteworthy
influence on the reaction performance.[14c,e] In this work, we
chose the most stable and preferential facets for calculations,
i.e., the (111) plane of Pt-Fe and the (111) plane of Pt-Ni3, based
on the results of HRTEM, XPS and previous literatures,[7d,14]
which can represent the surface catalytic property. Besides, the
calculated charge distribution and reaction routes are consistent
with the experimental data, which also further verifies the
rationality of the constructed catalyst models. The crystalline
phase structure, electronic Density of States (DOS), Electron
Localization Function (ELF) and Bader charge analysis of Pt-Fe
and Pt-Ni3 are presented in Figure 3, Figure S4, Figure S5 and
Table S1 (DFT models and calculations setup were described in
Supporting Information). As shown in Figure 5c and 5d, the Total
Densities of States (TDOS) and Partial Density of States
(PDOS) indicate that the bonding peaks of the Pt-Fe and Pt-Ni3
main contribution come from the hybridized d-orbitals of the Pt
and Fe, Pt and Ni atoms, respectively. The Bader charge of pure
Pt element is 10, which indicate that Pt element gains extra
charge from iron and nickel, respectively. Briefly, the Bader
charge analysis illustrates that in both cases the electrons
transfer from Fe or Ni to Pt lead to the electronegativity
difference, which is consistent with that of XPS. The ELF
calculation has often been employed as a robust indicator for
characterizing the chemical bonding and degree of electron
localization.[18] The ELF=0 represents the delocalized system
and ionic bonding between the atoms, however, the ELF=1.0
characterizes the completely electron localization and the
covalent bonds between the atoms, besides, ELF=0.5
represents the uniform electron gas and the presence of metal
bonds.[19] Figure 3e and 3f are the 2D ELF map on (111) planes
of the Pt-Fe and Pt-Ni3. Here the blue area indicates the charge
depletion and the red area indicates the charge accumulation.
Distinctly, after introducing the Fe, the degree of electron
localization for Pt atoms is obviously improved, enhancing the
chemical bonding strength between the Pt and Fe atoms.[20]
Figure 4. (a) Hydrogenation of cinnamaldehyde-reaction pathways; (b) Control
and blank experiments of the SH of CAL (Reaction conditions: Catalyst (25
mg), CAL (0.132 g, 1 mmol), ethyl acetate (10 mL), H2 (2 MPa), 2 h and
100 °C. Other product refers to cinnamaldehyde diethyl acetal).
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explained by the fact that the Lewis acidity, porosity and high
surface area of the UiO-66 are beneficial for the interaction
between the metal sites and support. Furthermore, the
dispersion of active sites was measured by CO pulse
chemisorption, which was employed to calculate turnover
frequency (TOF). Figure 5b gives the specific TOFs obtained
under similar reaction conditions for describing the intrinsic
activity of the Pt-based bimetallic catalysts. As reported in the
recent literature, the TOFs of 14753 h-1 for hydrogenating CAL to
COL was achieved by CoxFe1-xAl2O4+δ.
[21e] Herein, we give the
specific TOFs of the recent Pt-based bimetallic catalysts. The
TOFs of 1670 h-1 and 3048 h-1 are achieved under Pt-Fe/UiO-66
and Pt-Ni3/UiO-66, respectively, although the higher TOFs of
5544 h-1 for hydrogenating CAL to COL was achieved by
PtFe0.25/Al2O3@SBA-15.[6c] These results indicated the catalytic
selectivity and turnover frequency of Pt-Fe(Ni3)/UiO-66 were
higher than the values achieved in other catalysts as
summarized in Figure 5b and Table S5.[6,8,9,21]
We were intrigued by the great success in selective
cinnamaldehyde hydrogenation towards potential products in a
highly on-demand fashion. In order to further explore the general
applicability of Pt-Fe/UiO-66 and Pt-Ni3/UiO-66, a variety of
other unsaturated carbonyl compounds were also performed as
substrates under the optimized condition, and the performance
were shown in Table 1. The results indicated that the conversion
of other substrates were up to more than 90%. In the presence
of Pt-Fe/UiO-66 catalyst, the selectivity of unsaturated alcohols
were over 80%. Naturally, Pt-Ni3/UiO-66 displays contrasting
selectivity (over 81%) of saturated aldehydes. Corresponding
1HNMR spectra for the products were supplied in Supporting
Information (Figure S18-S27).
Figure 5. Comparison of (a) catalytic selectivity and (b) turnover frequency
(TOF) for SH of CAL over Pt-based bimetallic catalysts with different supports
(Pink area (left): Selectivity of COL; Cyan area (right): Selectivity of HCAL).
Data have been obtained from refs 13-15, 21-23, and this work.
Subsequently, the doping molar ratio of bicomponents was
carefully optimized, and the metallic content were measured by
ICP-AES (Figure S6, Table S3 and S4). With the increase of Pt
content, the conversion of CAL was significantly improved, but
the selectivity was scattershot. It is exciting that the presence of
Fe can enhance the selectivity of COL (Figure S6a).
Simultaneously, the influences of different reduction temperature
and time for the SH of CAL were investigated in Figure S7 and
S8. When Pt-Fe/UiO-66 was employed as catalyst, we achieved
a full conversion (99.9%) and satisfactory selectivity (94.3%)
within 4 hours. In addition, in order to adjust the product
distribution to obtain HCAL, the molar ratio of Pt-Ni was
investigated in Figure S6b. The results showed that the Ni
species in Pt-Ni/UiO-66 played a key role in the transformation
of CAL to HCAL. When the Pt-Ni molar ratio was 1:3, the
conversion of CAL was 99.9% and the selectivity of HCAL was
93.8%.
Table 1. Scope of substrates in SH of α,β-unsaturated carbonyl compounds
over Pt-Fe/UiO-66 and Pt-Ni3/UiO-66.[a]
Substrates
Pt-Fe/UiO-66[b]
Pt-Ni3/UiO-66
Conv. 99.9%, Sel. 94.3%
Conv. 99.9%, Sel. 93.8%
(1)
The recycling experiment of Pt-Fe(Ni3)/UiO-66 catalysts, as
shown in Figure S9a and 9b, were further investigated within
short time. The conversion of CAL exhibited a slight decrease
but the selectivity of target products kept almost unchanged after
being recycled for five times, which indicates that Pt-Fe/UiO-66
and Pt-Ni3/UiO-66 catalysts possess excellent catalytic durability.
Moreover, the recycled catalysts were also characterized by
XRD, FT-IR and HRTEM techniques, and the results further
demonstrated the Pt-Fe(Ni3)/UiO-66 catalysts were stable in the
suitable catalytic reaction condition (Figure 2d, 2e and S10).
The structure, morphology and composition of the supports
have important effects on the catalytic properties. For
comparison, ZrO2/CNT-supported Pt-Fe and Pt-Ni3 bimetallic
catalysts (Pt-Fe/ZrO2, Pt-Ni3/ZrO2, Pt-Fe/CNT, Pt-Ni3/CNT) were
prepared. Figure 5 and Table S5 show the comparison of
catalytic selectivity and turnover frequency (TOF) for SH of CAL
over Pt-based bimetallic catalysts with different supports. As can
be observed, Pt-based bimetals supported on zirconium-organic
frameworks (UiO-66) showed higher conversion and selectivity
than those supported on conventional carriers. This was
Conv. 99.9%, Sel. 90.7%
Conv. 99.9%, Sel. 95.1%
Conv. 96.2%, Sel. 87.2%
(2)
(3)
Conv. 92.5% Sel. 85.3%
Conv. 90.4%, Sel. 80.2%
Conv. 93.8%, Sel. 85.3%
(4)
(5)
Conv. 99.9%, Sel. 81.2%
Conv. 99.9%, Sel. 82.5%
[a] Reaction conditions: Catalyst (25 mg), Substrates (1 mmol), ethyl acetate
(10 mL), 100 °C and 2 MPa H2, 2 h). [b] The reaction time is 4 h.
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kJmol-1 over Pt/Fe3O4 catalyst.[21b] For the Pt-Ni3/UiO-66 catalytic
system, the Ea has been calculated to be 19.9 kJ/mol. This value
agreed with the findings of Fu et al., who reported an Ea of 18.8
kJmol-1 over 3.5 wt%Pt/G catalyst.[22] In comparison to Pt- and
Pd-based catalysts, the lower Ea values suggest Pt-Fe(Ni3)/UiO-
66 catalysts are quite suitable for selective hydrogenation of
CAL.
The possible reaction routes of CAL adsorption and
activation with the Pt-Fe(Ni3)/UiO-66 catalyst, according to the
aforementioned discussion, were also proposed in Figure 7. Pt
species have partially occupied d-orbitals, which can donate d-
electrons to the σ* antibonding orbital of H2, resulting in
weakening and cleaving H-H bonds, forming hydrides.[4a,7a]
Adsorption and activation of CAL on the catalyst surface was
based on the types of the active metals related to different
adsorbed patterns (Figure S13 and Figure 7a-d).[5a,23] Among
these adsorption patterns, the C=C π-complex and di-σ mode
can facilitate the preferential activation of C=C bonds. However,
the di-σCO and end-on mode enhanced the reactivity for C=O
group and generated the desired alcohols. For the Pt-
Fe(Ni3)/UiO-66 catalytic system, C=O group was activated and
weakened via end-on bonding interaction (ΔEads = –0.45 eV) on
the electron-deficient Fe surface, which attributed to the lone
pair of oxygen for carbonyl group can be attracted preferentially
because of anticlinal folded Pt-Fe skin (Figure S14).[24]
Meanwhile, the dissociated hydrogen molecules are transferred
to attack and activate CAL to form COL. For the Pt-Ni3/UiO-66
catalytic system, the differences in product distribution can be
rationalized based on the extended Huckel calculations of
Delbecq and Sautet. As shown in Table S6, Ni species showed
unstable four-electron interactions due to a narrower d-band
width compared to Fe, and the strong interactions between the
conjugated C=C bond and the Ni surface form di-σ mode (ΔEads
= –1.18 eV) lead to the favorable adsorption behavior of C=C
group, thereby notably enhancing the catalytic selectivity of
CAL.[5a,25]
Figure 6. (a, c) Kinetic profiles of the CAL conversion by the Pt-Fe(Ni3)/UiO-66
catalyst (X, CAL conversion) and (b, d) Arrhenius plot of formation of COL
from CAL at different temperature. Reaction conditions: Catalyst (25 mg), CAL
(0.132 g, 1 mmol), ethyl acetate (10 mL) and 2 MPa H2.
The kinetic curves of CAL hydrogenation under different
temperature (363, 368, 373, and 378 K) and corresponding
Arrhenius plots are displayed in Figure 6.[21b,22] The –ln(1 – X) is
proportional to the reaction time t, where X represents CAL
conversion. This plot is in accordance with the definition of a
first-order reaction. On the basis of this curve, the rate constants
k at different temperatures can be calculated. As we all known,
the Arrhenius equation is expressed as lnk = lnA – Ea/RT, where
Ea and A represent reaction apparent activation energy and pre-
exponential factor, respectively. For the Pt-Fe/UiO-66 catalytic
system, the value of Ea is 37.6 kJ mol-1, which slightly higher
than the findings of Zhao et al., who reported an Ea of 24.7
Figure 7. Optimized adsorption patterns of CAL on the surface of Pt-Fe (111) (a-b) and Pt-Ni3 (111) (c-d); The corresponding adsorption energies are labelled; (e)
The possible reaction routes for SH of CAL to COL or HCAL on the surface of Pt-Fe/UiO-66 and Pt-Ni3/UiO-66, respectively.
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Fe(111) structural model was built using a quadruple-layer p(5×5) slab
with 4 metal layers. Furthermore, a vacuum of 15 Å in the z direction was
built to separate the neighboring cells. The Pt-Ni3(111) structural model
was built also by p(5×5) supercell with 4 layers. The cutoff energies were
set to be 400 eV, which have been tested extensively in supporting
information (Figure S16 and S17). The Monkhorst-Pack k-point sampling
were set to be 4×4×1 and 6×3×1 for Pt-Fe and Pt-Ni3 models,
respectively. The convergence criteria for the ionic relaxation loop and
electronic self-consistent iteration were set to 10-4 eV and 10-5 eV/Å,
respectively. The stability of the adsorbed CAL on the catalyst surface
was described via chemisorption energy ΔEads, which is defined by the
following equation:
Conclusion
In summary, the structurally alloyed Pt-Fe(Ni3)/UiO-66 catalysts
show unique electronic structure and catalytic properties for SH
of α,β-unsaturated aldehydes in comparison with single-
component Pt catalyst. For the SH of cinnamaldehyde, Fe favors
C=O bond hydrogenation (conv. 99.9%, sel. 94.3%), while Ni
was more selective for C=C bond hydrogenation (conv. 99.9%,
sel. 93.8%) on-demand. Comprehensive characterizations and
periodic DFT calculations demonstrate that charge density of Pt
species is recombinated after introducing 3d-transition metals
(Fe, Ni), which is essential for the high chemoselectivity of
cinnamaldehyde to cinnamic alcohol and phenylpropanal,
respectively. This study provides an important insight related to
rational control of catalytic selectivity via bicomponent
nanocatatalysts with precise electron modification, enhanced
catalytic properties. Besides, the introducing of secondary
component not only directly reduces the expensive Pt usage in
the environment-benign catalysts, which emerges satisfactory
industrial application potential.
ΔEads = Eslab+cal – Eslab – Ecal
Where Eslab+cal is the energy of the catalyst with the adsorbed CAL, Eslab
is the energy of pure catalyst, and Ecal is the energy of the isolated CAL.
Acknowledgements
This work was supported by the National Natural Science
Foundation of China (21601135, 21875117).
Keywords: Bimetallic catalysts • MOFs • Selectivity
hydrogenation • Electronic effects • DFT
[1] a) L. L. Zhang, M. X. Zhou, A. Q. Wang, T. Zhang, Chem. Rev. 2020,
2, 683 – 733; b) M. T. Zhao, K. Yuan, Y. Wang, G. D. Li, J. Guo, L. Gu, W.
P. Hu, H. J. Zhao, Z. Y. Tang, Nature 2016, 539, 76 – 80; c) X. C. Lan, T.
F. Wang, ACS Catal. 2020, 10, 2764 – 2790; d) X. M. Ren, M. Guo, H. Li,
C. Li, L. Yu, J. Liu, Q. H. Yang, Angew. Chem., Int. Ed. 2019, 58, 1 – 7;
Angew. Chem. 2019, 131, 14625 – 14630.
Experimental Section
Catalyst preparation
The UiO-66 was prepared according to the previous report.[12b]
Experimental details and structure information of UiO-66 is provided in
supporting information (Figure S15). On the other hand, 10.0 mg (0.02
mmol) of H2PtCl6·6H2O, 5.4 mg (0.02 mmol) of FeCl3·6H2O, 2 mL of PVP
aqueous solution (0.3 wt %), and 100 mL of deionized water, were added
to 250 mL flask. Subsequently, 2.5 mL of NaBH4 aqueous solution (0.1
mol/L) was added drop by drop after stirring at room temperature for 1 h.
After stirring for another 1 h, 0.1 g of UiO-66 powder was added. Stirring
was continued at room temperature overnight, and product was collected
through filtration (8000 r/min, 5 min), washed by ethanol and distilled
water three times, dried in vacuum for 24 h at 80 ℃, then pyrolyzed in air
for 2 h at 300 ℃.
The strategy for the preparation of Pt-Ni3/UiO-66 was similar to that
of Pt-Fe/UiO-66 except that NiCl2∙6H2O (7.6 mg, 0.06 mmol) was used
instead of FeCl3∙6H2O.
The strategy for the preparation of Pt-Fe(Ni3)/ZrO2 and Pt-
Fe(Ni3)/CNT were similar to that of Pt-Fe/UiO-66 except that UiO-66 was
used instead of ZrO2 and CNT.
The strategy for the preparation of Pt-Co(Co3)/UiO-66 and Pt-
Sn(Sn3)/UiO-66 were similar to that of Pt-Fe(Ni3)//UiO-66.
Meanwhile, single-component Pt/UiO-66, Fe/UiO-66 and Ni/UiO-66
were synthesized by the similar aforesaid protocol without second metal
(Fe, Ni) introducing.
For comparison, MOFs-supported bicomponent catalysts with
Pt:Fe(Ni) nominal molar ratios of 4:1, 3:1, 2:1, 1:1, 1:2, 1:3 and 1:4 were
synthesized via aforementioned method.
[2] A. J. Muller, J. S. Bowers Jr, J. R. I. Eubanks, C. C. Geiger, J. G.
Santobianco, WO Patent Appl. No. WO 99/08989, 1999, First Chemical
Corporation.
[3] X. F. Wang, X. H. Liang, P. Geng, Q. B. Li, ACS Catal. 2020, 10, 2395 –
2412.
[4] a) W. L. Zhang, W. X. Shi, W. L. Ji, H. B. Wu, Z. D. Gu, P. Wang, X. H. Li,
P. S. Qin, J. Zhang, Y. Fan, T. Y. Wu, Y. Fu, W. N. Zhang, F. W. Huo,
ACS Catal. 2020, 10, 5805 – 5813; b) M. Macino, A. J. Barnes, S. M.
Althahban, R. Y. Qu, E. K. Gibson, D. J. Morgan, S. J. Freakley, N.
Dimitratos, C. J. Kiely, X. Gao, A. M. Beale, D. Bethell, Q. He, M. Sankar,
G. J. Hutchings, Nat. Catal. 2019, 2, 873 – 881.
[5] a) F. Delbecq, P. Sautet, J. Catal. 1995, 152, 217–236; b) F. Delbecq, P.
Sautet, J. Catal. 1996, 164, 152 – 165; c) K. Yuan, T. Q. Song, D. W.
Wang, X. T. Zhang, X. Gao, Y. Zou, H. L. Dong, Z. Y. Tang, W. P. Hu,
Angew. Chem., Int. Ed. 2018, 57, 5708 – 5713; Angew. Chem. 2018, 130,
5810 – 5815.
[6] a) Y. H. Peng, Z. G. Geng, S. T. Zhao, L. B. Wang, H. L. Li, X. Wang, X. S.
Zheng, J. F. Zhu, Z. Y. Li, R. Si, J. Zeng, Nano Lett. 2018, 18, 3785 –
3791; b) Z. Z. Gu, L. Y. Chen, X. Z. Li, L. Chen, Y. Y. Zhang, C. Y. Duan,
Chem. Sci. 2019, 10, 2111 – 2117; c) H. Y. Pan, J. R. Li, J. Q. Lu, G. M.
Wang, W. H. Xie, P. Wu, X. H. Li, J. Catal. 2017, 354, 24 − 36; d) P. T.
Wang, Q. Shao, X. N. Cui, X. Zhu, X. Q. Huang, Adv. Funct. Mater. 2018,
5, 1705918; e) Q. M. Hu, S. Wang, Z. Gao, Y. Q. Li, Q. Zhang, Q. Xiang,
Y. Qin, Appl. Catal., B 2017, 218, 591 – 599.
[7] a) H. P. Wang, S. X. Bai, Y. C. Pi, Q. Shao, Y. M. Tan, X. Q. Huang, ACS
Catal. 2019, 9, 154 − 159; b) X. Jin, M. Zhao, W. J. Yan, C. Zeng, P.
Bobba, P. S. Thapa, B. Subramaniam, R. V. Chaudhari, J. Catal. 2016,
337, 272 – 283; c) J. K. Zhang, Z. Gao, S. Wang, G. F. Wang, X. F. Gao,
B. Y. Zhang, S. F. Xing, S. C. Zhao, Y. Qin, Nat. Commun. 2019, 10, 4166
– 4174; d) Y. F. Xie, J. Y. Cai, Y. S. Wu, Y. P. Zang, X. S. Zheng, J. Ye, P.
X. Cui, S. W. Niu, Y. Liu, J. F. Zhu, X. J. Liu, G. M. Wang, Y. T. Qian, Adv.
Mater. 2019, 31, 1807780 – 1807786.
DFT Calculations
The structural models for the Pt-Fe and Pt-Ni3 nanostructure in the
present DFT calculation were constructed according to the previous
report.[5a, 25] All the crystalline phase structure, electronic density of states
(DOS), electron localization function (ELF) and Bader charge analysis
were calculated by the Vienna Ab-initio Simulation Package (VASP). The
generalized gradient approximation (GGA) of Perdew-Burke-Ernzerh
(PBE) was used to describe the exchange-correlation effects.[26] The Pt-
[8] a) X. X. Han, R. X. Zhou, B. H. Yue, X. M. Zheng, Catal. Lett. 2006, 109,
157 − 161; b) Y. Li, C. H. Ge, J. Zhao, R. X. Zhou, Catal. Lett. 2008, 126,
280 − 285.
7
This article is protected by copyright. All rights reserved.

10.1002/cctc.202001482
ChemCatChem
FULL PAPER
[9] a) Y. H. Dai, X. Gao, X. F. Chu, C. Y. Jiang, Y. Yao, Z. Guo, C. M. Zhou,
C. Wang, H. M. Wang, Y. H. Yang, J. Catal. 2018, 364, 192 − 203; b) J. P.
Stassi, P. D. Zgolicz, S. R. de Miguel, O. A. Scelza, J. Catal. 2013, 306,
11 – 29; c) X. F. Wang, Y. F. He, Y. Z. Liu, J. Park, X. H. Liang, J. Catal.
2018, 366, 61 – 69.
[10] T. N. Ye, J. Li, M. Kitano, M. Sasase, H. Hosono, Chem. Sci. 2016, 7,
5969 – 5975.
[11] a) H. C. Zhou, J. R. Long, O. M. Yaghi, Chem. Rev. 2012, 112, 673 – 674;
b) S. M. J. Rogge, A. Bavykina, J. Hajek, H. Garcia, A. I. Olivos-Suarez, A.
Sepúlveda-Escribano, A. Vimont, G. Clet, P. Bazin, F. Kapteijn, M. Daturi,
E. V. Ramos-Fernandez, F. X. Llabrés i Xamena, V. Van Speybroeck, J.
Gascon, Chem. Soc. Rev. 2017, 46, 3134 – 3184; c) L. Jiao, Y. Wang, H.
L. Jiang, Q. Xu, Adv. Mater. 2018, 30, 1703663 – 1703685.
[12] a) P. F. Ji, T. Drake, A. Murakami, P. Oliveres, J. H. Skone, W. B. Lin, J.
Am. Chem. Soc. 2018, 140, 10553 − 10561; b) J. H. Cavka, S. Jakobsen,
U. Olsbye, N. Guillou, C. Lamberti, S. Bordiga, K. P. Lillerud, J. Am. Chem.
Soc. 2008, 130, 13850 – 13851.
[13] L. M. Ning, S. Y. Liao, P. F. Guo, Z. Y. Zhang, H. G. Zhang, X. L. Tong, J.
Catal. 2018, 364, 1 – 13.
[14] a) Z. L. Guo, D. P. Liu, S. H. Lim, Y. Liu, W. Chu, Green Chem. 2019, 21,
5999 – 6011; b) G. M. Wang, H. Y. Xin, Q. X. Wang, P. Wu, X. H. Li, J.
Catal. 2020, 382, 1 – 12; c) S. X. Bai, B. L. Huang, Q. Shao, X. Q. Huang,
ACS Appl. Mater. Interfaces 2018, 10, 22257 – 22263; d) X. J. Zhao, Y.
Zhao, G. Fu, N. F. Zheng, Chem. Commun. 2015, 51, 12016−12019; e) Y.
Zhao, G. Fu, N. F. Zheng, Catal. Today 2017, 279, 36 – 44; f) K. J.
Jenkinson, A. Wagner, N. Kornienko, E. Reisner, A. E. H. Wheatley, Adv.
Funct. Mater. 2020, 2002633 − 2002639; g)J. F. Wen, Y. J. Chen, S. F. Ji,
J. Zhang, D. S. Wang, Y. D. Li, Nano Res. 2019, 12, 2584 – 2588.
[15] R. Q. Zou, H. Sakurai, S. Han, R. Q. Zhong, Q. Xu, J. Am. Chem. Soc.
2007, 129, 8402 – 8403.
[16] a) T. Gan, X. F. Chu, H. Qi, W. X. Zhang, Y. C. Zou, W. F. Yan, G. Liu,
Appl. Catal., B 2019, 257, 117943; b) B. Han, Y. L. Guo, Y. K. Huang, W.
Xi, J. Xu, J. Luo, H. F. Qi, Y. J. Ren, X. Y. Liu, B. T. Qiao, T. Zhang,
Angew. Chem., Int. Ed. 2020, 59, 11824 – 11829; Angew. Chem. 2020,
132, 11922 – 11927.
[17] Z. Y. Wu, W. W. Zhang, S. R. Sun, Comput. Mater. Sci. 2016, 125, 278 –
283.
[18] B. Qin, D. Wang, W. He, Y. Zhang, H. Wu, S. J. Pennycook, L. D. Zhao, J.
Am. Chem. Soc. 2019, 141, 1141 – 1149.
[19] E. Matito, M. Solà, Coord. Chem. Rev. 2009, 253, 647 – 665.
[20] a) Q. Bian, Z. H. Yang, L. Y. Dong, S. L. Pan, H. Zhang, H. P. Wu, H. W.
Yu, W. W. Zhao, Q. Jing, J. Phys. Chem. C 2014, 118, 25651 – 25657; b)
Z. X. Ren, J. Q. Qin, R. P. Liu, X. Y. Zhang, J. Alloys Compd. 2020, 825,
153825 – 153833.
[21] a) V. R. Bakuru, S. B. Kalidindi, Chem. - Eur. J. 2017, 23,16456 – 16459;
b) Y. W. Zhang, S. P. Wei, Y. J. Lin, G. L. Fan, F. Li, ACS Omega. 2018, 3,
12778 − 12787; b) Y. Zhang, C. Chen, W. B. Gong, J. Y. Song, Y. P. Su,
H. M. Zhang, G. Z. Wang, H. J. Zhao, RSC Adv. 2017, 7, 21107 − 21113;
c) S. Bhogeswararao, V. Pavan Kumar, K. V. R. Chary, D. Srinivas, Catal.
Lett. 2013, 143, 1266 − 1276; d) S. X. Bai, L. Z. Bu, Q. Shao, X. Zhu, X. Q.
Huang, J. Am. Chem. Soc. 2018, 140, 8384 – 8387; e) H. Y. Xin, Y. J.
Xue, W. B. Zhang, P. Wu, X. H. Li, J. Catal. 2019, 380, 254 – 266.
[22] X. W. Ji, X. Y. Niu, B. Li, Q. Han, F. L. Yuan, F. Zaera, Y. J. Zhu, H. G. Fu,
ChemCatChem 2014, 6, 3246 – 3253.
[23] W. Liu, Y. D. Jiang, K. H. Dostert, C. P. O’Brien, W. Riedel, A. Savara, S.
Schauermann, A. Tkatchenko, Sci. Adv. 2017, 3, 1700939 – 1700945.
[24] W. S. Putro, T. Kojima, T. Hara, N. Ichikuni, S. Shimazu, Catal. Sci.
Technol. 2017, 7, 3637 – 3646.
[25] U. K. Singh, M. A. Vannice, J. Catal. 2001, 199, 73 – 84.
[26] a) M. P. Humbert, J. G. Chen, J. Catal. 2008, 257, 297–306; b) L. H. Ou,
Comput. Theor. Chem. 2014, 1048, 69 – 76.
[27] a) G. Kresse, J. Hafner, Phys. Rev. B 1994, 49, 14251 – 14269; b) G.
Kresse, J. Furthmꢀller, Comput. Mater. Sci. 1996, 6, 15 – 50; c) J. P.
Perdew, K. Burke, M. Ernzerhof, Phys. Rev. Lett. 1996, 77, 3865 – 3868;
d) G. Kresse, D. Joubert, Phys. Rev. B: Condens. Matter Mater. Phys.
1999, 59, 1758 – 1775; e) P. E. Blꢁchl, Phys. Rev. B 1994, 50, 17953 –
17979.
8
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Entry for the Table of Contents
In this work, we report a convenient strategy to fabricate bimetallic nanostructures with 3d-transition non-noble metal (Fe, Ni)
modified Pt nanoparticles directly supported on porous metal-organic frameworks, which can function as a switch for selective
hydrogenation of α,β-unsaturated aldehydes towards potential products on-demand.
9
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