Visible-Light Direct Conversion of Ethanol to 1,1-Diethoxyethane and Hydrogen over a Non-Precious Metal Photocatalyst

Article abstract of DOI:10.1002/chem.201804664

Converting renewable biomass and their derivatives into chemicals and fuels has received much attention to reduce the dependence on fossil resources. Photocatalytic ethanol dehydrogenation–acetalization to prepare value-added 1,1-diethoxyethane and H₂ was achieved over non-precious metal CdS/Ni-MoS₂ catalyst under visible light. The system displays an excellent production rate and high selectivity of 1,1-diethoxyethane, 52.1 mmol g^?1 h^?1 and 99.2 %, respectively. In-situ electron spin resonance, photoluminescence spectroscopy and transient photocurrent responses were conducted to investigate the mechanism. This study provides a promising strategy for a green application of bioethanol.

Full text of DOI:10.1002/chem.201804664

A Journal of
Accepted Article
Title: Visible light Direct Conversion of Ethanol to 1,1-Diethoxyethane
and Hydrogen over Non-Precious Metal Photocatalyst
Authors: Yuguang Chao, Wenqin Zhang, Xuemei Wu, Nana Gong,
Zhihong Bi, Yunqin Li, Jianfeng Zheng, Zhenping Zhu, and
Yisheng Tan
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Chem. Eur. J. 10.1002/chem.201804664
Link to VoR: http://dx.doi.org/10.1002/chem.201804664
Supported by

10.1002/chem.201804664
Chemistry - A European Journal
DOI: 10.1002/((please add manuscript number))
Article type: Communication
Visible light Direct Conversion of Ethanol to 1,1-Diethoxyethane and Hydrogen over Non-
Precious Metal Photocatalyst
Yuguang Chao, Wenqin Zhang, Xuemei Wu, Nana Gong, Zhihong Bi, Yunqin Li, Jianfeng Zheng,*
Zhenping Zhu and Yisheng Tan*
Y. Chao, W. Zhang, X. Wu, N. Gong, Y. Li, Prof. J. Zheng, Prof. Z. Zhu, Prof. Y. Tan
State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of
Sciences, Taiyuan, 030001, China.
Y. Chao, X. Wu, N. Gong, Z. Bi
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Z. Bi
Key Laboratory of Carbon Material, Institute of Coal Chemistry, Chinese Academy of Sciences,
Taiyuan 030001, PR China
Keywords: visible light; non-precious metal; ethanol; photocatalytic; 1,1-diethoxyethane
Abstract: Converting renewable biomass and their derivatives into chemicals and fuels has received
much attention to reduce the dependence on fossil resources. We report an efficient and green atom
economic process achieved over non-precious metal CdS/Ni-MoS2 catalytic under visible light.
Renewable H2 and value-added 1,1-diethoxyethane are obtained at the same time by photocatalytic
water splitting with ethanol as sacrificial agent. The system displays an excellent production rate and
high selectivity of 1,1-diethoxyethane, 52.1 mmol g−1 h−1 and 99.2%, respectively. In-situ electron
spin resonance, photoluminescence spectroscopy and transient photocurrent responses are conducted
to investigate the mechanism. This study provides a promising strategy for atomic green economy
application of bio-ethanol.
The conversion of solar energy to electric energy and chemical energy has become the hot topic of
research in today's society.[1-10] Converting water into renewable hydrogen (H2) fuel by
photocatalytic water splitting, inspired by natural photosynthesis, has been considered as a promising
avenue to settle the energy and environmental issues, attracting ebullient attention in recent
1
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
decades.[11-15] However, sacrificial agent (e.g., methanol and ethanol) need adding to improve the
efficiency of solar-to-H2 in most reaction systems.[16-22] The main function of these sacrificial agents
is capturing photogenerated holes to accelerate water oxidation kinetics. Unfortunately, the majority
of sacrificial agent is oxidized to CO or CO2, which is harmful to environment.[23,24] As one of the
most important bio-alcohols, ethanol contains 13.04 wt% of hydrogen, being perceived as a potential
hydrogen storage medium, obtained from biomass fermentation.[25] Therefore, photocatalytic ethanol
dehydrogenation, converting into value-added chemicals without COx release, is a logical strategy to
solve the problems above.
1,1-diethoxyethane (DEE), a value-added derivative product of the ethanol selective oxidation,
has drew intense attention recently, due to its multidisciplinary applications in pharmaceuticals, fuel
additive, fragrance industry and intermediate for chemical synthesis.[26-28] Particularly, DEE is
regarded as a remarkable additive to replace ethanol in fuel, for it can keep or increase the cetane
number of the fuel[29] and combust the resulting mixtures more drastically.[30] Interestingly, as an
additive into fuel, DEE can also drastically inhibit the emission of nitrogen oxide.[31] All these
features indicate that the conversion into DEE is a promising channel for the rational utilization of
bioethanol. However, the traditional conversion of ethanol into DEE process requires two steps:
ethanol was selectively oxidized to aldehyde and then acid catalyzed aldehyde–ethanol acetalization
as DEE.[31-33] In this traditional process, the oxidation step is highly damaging to environment, the
system is really complex and strict in terms of reactor equipment. Therefore, it is urgent requirement
for exploiting a simple method to convert ethanol to DEE green and economically.
Photocatalytic acetal reaction supplies a novel strategy to convert ethanol into acetal effectively.
Our group achieved visible light driven methanol dehydrogenation–acetalization, converting into
1,1-dimethoxymethane and H2 over noble metal-free photocatalyst CdS/Ni2P nanostructured in one
step.[34] Zhang and coworkers demonstrated that Pd/TiO2 nanostructures are highly photoactive for
the dehydrogenation C-O coupling of ethanol into DEE.[31,35,36] Xu's group reported that the
2
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
decoration of Pd nanocubes onto TiO2 nanosheets allows simultaneous DEE production and H2
evolution under ultraviolet light.[37] However, the only ultraviolet light response of TiO2 and the
expensive noble metal co-catalysts restrict the large-scale actual application of photocatalytic acetal
reactions.
In this work, ethanol is converted into DEE and H2 over non-precious metals CdS nanorods/Ni-
MoS2 nanosheets via photocatalytic dehydrogenation–acetalization under visible light. A small
amount of sulphuric acid exists in the reaction system. The acid can not only drive the
dehydrogenation of ethanol, but also catalyze the acetalization reaction. The rate and selectively of
photocatalytic DEE evolution reaches 52.1 mmol g−1 h−1 and 99.2%, respectively, while the H+
concentration is 30 mM. Simultaneously, the trace acid in the reaction system does not corrode the
catalyst and glass reactor at all.
The well shaped CdS nanorods were synthesized on the basis of previously reported method,[38]
serving as photocatalyst. The Ni-MoS2 nanosheets were loaded onto CdS nanorods in-situ through
the solvothermal reaction with L-cysteine, Na2MoO4·2H2O and Ni(NO3)·6H2O as precursors at
200 °C for 30 h. The field-emission scanning electron microscopy (FESEM) (Figures 1a and S1)
and transmission electron microscopy (TEM) images (Figures S2a and S2b) shown that the as-
prepared CdS was uniform well-shaped 1D nanorods with the average diameter of about 30-40 nm.
Figure 1b and 1c clearly presented the FESEM and TEM images of CdS nanorods after growing Ni-
MoS2 nanosheets on their surface, and the nanorods kept their 1D geometries. High-resolution
transmission electron microscopy (HRTEM) image (Figure 1d) shown a lattice spacing of about
0.34 nm consistent with the (002) plane of hexagonal CdS, and lattice spacing of about 0.64 nm,
coinciding with the (002) plane of Ni-MoS2 nanosheets. X-ray diffraction (XRD) was carried out to
investigate the crystal structures of the as-made photocatalysts nanostructure. All characteristic peaks
were well in agreement with the standard card of hexagonal CdS (JCPDS card No. 41-1049) (Figure
S3). Nevertheless, no obvious diffraction peaks were attributed to Ni-MoS2 in the XRD patterns and
3
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
no significant diffraction peaks were different from those of the CdS nanorods after the co-catalyst
loaded, probably due to the relatively small amount of Ni-MoS2 distribution and too strong
diffraction peaks of the CdS nanorods.[39-41] In addition, we specialized in the synthesis of Ni-MoS2
without CdS nanorods addition, and XRD pattern unveiled that the nickel was doped in the MoS2,
due to no obvious characteristic peaks of NiS (Figure S4), which was in agreement with a previous
report.[42]
X-ray photoelectron spectroscopy (XPS) was employed for investigating the chemical state of
the as-made CdS/Ni-MoS2 nanostructure. The survey scan displayed the existence of Cd, S, Mo, Ni
elements in the as-prepared CdS/Ni-MoS2 (Figure S5a). The binding energy peaks of Mo 3d3/2 and
Mo 3d5/2 were located at 231.4 and 228.2 eV (Figure S5b), respectively, while that of S 2p3/2 and S
2p1/2 peaks located at 161.1 and 162.4 eV (Figure S5c). These results suggested that the valence
states of the Mo and S elements in the final Ni-MoS2 nanosheets were Mo4+ and S2−.[43,44] It can be
observed from the Ni 2p spectra shown in Figure S5d that the Ni 2p3/2 binding energy of 853.4 eV
corresponded to the Ni in the Ni–Mo–S structure.[45] The UV–vis diffuse reflectance spectra (DRS)
of the as synthesized samples were shown in Figure S6, and all the photocatalysts samples
performed strong absorption in the region from 200–520 nm, assigning to the intrinsic bandgap
absorption of CdS nanorods. Notability, loading the Ni-MoS2 co-catalysts onto the surface of CdS
nanorods could obviously increase the absorption of samples in visible light region of 520 to 800 nm.
This was beneficial to improve the activity of photocatalytic ethanol dehydrogenation.
The photocatalytic ethanol dehydrogenation coupling over the CdS/Ni-MoS2 nanocomposites
had been performed in ethanol media (containing different concentration of H+) under visible light
irradiation (λ > 420 nm). Different amounts of co-catalyst Ni-MoS2 nanosheets had been covered on
CdS nanorods to investigate the optimum weight percent of Ni-MoS2 to enhance the photoactivity of
catalysts with the concentration of H+ is 30 mM, as shown in Figure 2a. The photocatalytic H2
production exhibited a improved tendency with increasing Ni-MoS2 content. Nevertheless, the
4
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
excess co-catalyst might reduce the light absorption of CdS nanorods and served as recombination
centre for charge carriers, indicating that an suitable co-catalyst content is of importance for
optimizing the photo-activity of CdS/NiMoS2.[34] Thereby, the photocatalyst achieved a optimal
value at the weight content of 7 wt%, the H2 production rate reaches an optimal value of up to 52.1
mmol g−1 h−1, and this result was in accordance with the UV-vis spectrum (Figure S6). The
durability of CdS/NiMoS2 catalyst was studied by four consecutive cycles with each cycle of four
hour under visible light irradiation (Figure 2b). At the end of each run, the reactor was evacuated
and then refilled with Ar, but the catalyst was not treated. No obvious deactivation was observed
within four repeated cycles of photocatalysis, and the crystalline structures of CdS/NiMoS2
photocatalyst before and after 4 cycles photocatalytic reaction had no significant change (Figure S7),
indicating the outstanding photo-stability of the CdS/NiMoS2 under acid condition and potential for
long-term photocatalytic actual applications.
During photocatalytic H2 evolution from ethanol dissociation, ethanol could be converted into
value-added 1,1-diethoxyethane (DEE) in the presence of acid (sulphuric acid). The chemical
compositions of the liquid products were analyzed by utilizing GC-MS, as shown in Figure S8 and
Figure S9. The main liquid phase products were DEE and aldehyde. As H+ played important roles in
catalyzing the acetal reaction,[35,46] we investigated the effect with various H+ concentrations on the
production rate and the selectivity of DEE. As shown in Figure 3a, the rate of DEE production was
increasing with the increase of H+ concentration, and it was worth noting that the rate of DEE
production can reach 52.1 mmol g-1 h-1 in 30 mM H+ ethanol solution. However, the selectively had
no obvious change at the different H+ concentration (Figure 3b), which maintains 99.2%. The high
selectively was ascribed to the rapid reaction of ethanol with the product of the dehydrogenation of
ethanol in the presence of H+. In addition, the yield of ethanol conversion can reach to 5% after 12
hours reaction. Interesting, we did not detect the any carbon oxide in the photocatalysis process, and
the only by-product was aldehyde. Moreover, taking the selectivity of DEE into consideration, the
5
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
rate of DEE evolution was similar to that of H2, maintaining a rate ratio of 1 : 1, indicating the
photocatalytic process proceeded nearly by following the chemical equation shown below, according
with the previous report:[25]
CH2
CH2
CH3
CH3
O
O
hv
H+
CH3
HC
3CH3CH2OH
H2
H2O
+
+
In addition, the effect of acid species added in ethanol solution was also investigated. It is
clearly visible that, when the H+ ions were supplied by HCl aqueous solution (36-38%), both the rate
and selectively of DMM production decreased (Figure S10). The reason was the fast hydrolysis of
DEE to acetaldehyde (inverse reaction) in the presence of water, which was introducd by
hydrochloric acid aqueous solution, thereby HCl aqueous solution was not a ideal medium to adjust
the pH of reaction system.[31,34] Moreover, when no acid was added in the ethanol solution, the rate
of photocatalytic H2 evolution decreased sharply and no DEE was detected in liquid product. The
ethanol dehydrogenation and conversion into butane-2,3-diol and aldehyde (Figures S11 and S12),
and the selectivity of butane-2,3-diol and aldehyde were 46.8% and 53.2%, respectively. This
photocatalytic ethanol dehydrated path was consistent with the previous report.[35,47,48] This process
also exhibited an excellent photocatalytic H2 evolution stability, having no obvious decrease as long
as for 18 h (Figure S13).
To exploring the mechanism of photocatalytic ethanol converting into DEE and H2, an in-situ
electron spin resonance (ESR) was conducted for the analysis of the reaction intermediates radicals.
Figure 4 displayed the ESR spectrum during the process of photocatalytic ethanol dehydrogenation
coupling reaction by using 5, 5-dimethyl-1-pyrroline N-oxide (DMPO, 0.05 M) capturing the
reaction intermediates radicals over the CdS/NMS7 photocatalyst. The ESR result shown the
existence of hydroxyl ethyl radical ﹒(CHOHCH3) (aN = 15.4, aH = 22) in the photocatalysis process,
which was identical with the Zhang’s report.[36] This intermediate should be formed in dissociating
one H atom from ethanol (α-H) by the oxidation of photo-generation holes. This radical continued to
6
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
dissociate another α-H by the further oxidation, forming one stable aldehyde molecule. Meanwhile,
no ethoxy radical was detected, indicating the dehydrogenation occurring at α-H, but not O-H.
Thereby, the value-added DEE could be obtained from the reaction of the generated aldehyde and
ethanol under acid condition.
Photoluminescence (PL) spectroscopy and transient photocurrent responses were considered to
powerful techniques for investigating the separation and transfer of charge carriers. Fig. 5a shown
two distinct emission bands at ca. 530 nm and 640 nm, which could be attributed to near-band-edge
emission and the excess of sulfur or core defects on the nanorod surfaces, respectively. The PL
emission intensity exhibited an obvious decrease as the co-catalyst Ni-MoS2 loaded, indicating that
the co-catalyst Ni-MoS2 can improve the separation efficiency of photo-generated charge carries.
Notably, the CdS/NMS7 exhibited the optimal performance to enhance the separation of charge
carriers. The transient photocurrent responses were performed with interval 10 s periodic light on/off
cycle under visible light irradiation (Fig. 5b). The CdS/NMS7 exhibited the highest cathodic
photocurrent among all the as-prepared samples, even twice higher than the current of bare CdS
nanordos. The addition of co-catalyst Ni-MoS2 accelerated the electron separation and transfer
process, resulting in higher performance of photocatalytic ethanol dehydrogenation.
The probable mechanism of visible light-driven ethanol dehydrogenation-acetalization reaction
can be summarized by above results. CdS nanorods were excited by visible light, producing the
photo-generated charge carriers. The electron-holes pairs recombined quickly without the co-catalyst
loaded resulting relatively poor activity. When Ni-MoS2 was covered on the surface of CdS nanorods,
the charge carrier could be separated and transferred effectively. Therefore, the holes on the CdS
nanorods were easy to oxidize CH3CH2OH to generate the hydroxyl ethyl radical intermediate,
˙CH(OH)CH3. The intermediate were further oxidized to aldehyde (CH3CHO) because of their
dynamical instability property. Then the generated aldehyde reacts with ethanol rapidly to form DEE
under acidic conditions, while no acetic acid was detected and no COx was released in this reaction.
7
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
Meanwhile, the generated two protons transfer to the surface of the Ni-MoS2 nanosheets, followed
by reducing to H2 by the photo-generation electrons at the conduction band of the CdS nanorods.
Therefore, only value-added DEE and H2 generated in this photocatalytic ethanol dehydrogenation-
acetalization reaction, avoiding the environmental pollution occurring in traditional acid-catalyzed
acetalization processes.
In summary, photocatalytic ethanol dehydrogenation-acetalization reaction was achieved in one
step on non-precious metals CdS/Ni-MoS2 catalyst by visible light driven for the first time. The
value-added DEE and sustainable H2 were obtained in this atom economic green avenue. The
optimal photocatalyst CdS/NSM7 composite exhibits excellent rate and selectivity of DEE evolution
under a suitable acid condition ([H+] = 30 mM), which is 52.1 mmol g-1 h-1 and 99.2%, respectively.
There is no CO or CO2 detected in the gas phase products, avoiding the environmental pollution.
This work explores a viable strategy for the direct efficient conversion of ethanol into value-added
DEE and sustainable H2 by visible light driven, and provides a promising strategy for atomic
economy green application of bio-ethanol.
Supporting Information
Supporting Information is available from the Wiley Online Library or from the author.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China
(91545116 and 21573269).
Received: ((will be filled in by the editorial staff))
Revised: ((will be filled in by the editorial staff))
Published online: ((will be filled in by the editorial staff))
8
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
References
[1]
[2]
[3]
[4]
[5]
R. Chen, S. Pang, H. An, J. Zhu, S. Ye, Y. Gao, F. Fan, C. Li, Nat. Energy 2018, 8, 655.
A. Abate, J. P. Correa-Baena, M. Saliba, M. S. Su'ait, F. Bella, Chem. Eur. J. 2018, 24, 3083.
S. H. Li, N. Zhang, X. Xie, R. Luque, Y.-J. Xu, Angew. Chem. Int. Ed. 2018.
F. Bella, M. Imperiyka, A. Ahmad, J. Photoch. Photobio. A, 2014, 73.
A. Sacco, F. Bella, S. De La Pierre, M. Castellino, S. Bianco, R. Bongiovanni, C. F. Pirri,
Chemphyschem, 2015, 5, 960.
[6] G. Zhao, Y. Sun, W. Zhou, X. Wang, K. Chang, G. Liu, H. Liu, T. Kako, J. Ye, Adv. Mater.
2017, 40.
[7]
[8]
F. Bella, P. Renzi, C. Cavallo, C. Gerbaldi, Chem. Eur. J. 2018, 47, 12183.
X. Wang, H. Wang, H. Zhang, W. Yu, X. Wang, Y. Zhao, X. Zong, C. Li, ACS Energy Lett.
2018, 5, 1159.
[9]
D. Ompong, J. Singh, Organic Electronics 2018, 104.
[10] F. Bella, A. Sacco, G. Massaglia, A. Chiodoni, C. F. Pirri, M. Quaglio, Nanoscale 2015, 28,
12010.
[11] P. Zhou, J. Lai, Y. Tang, Y. Chao, F. Lin, S. Guo, Appl. Catal. B: Environ. 2018, 161.
[12] Y. Chao, J. Zheng, H. Zhang, Y. Ma, F. Li, Y. Tan, Z. Zhu, Energy Technol. 2018.
[13] N.S. Lewis, D.G. Nocera, Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 15729.
[14] Y. Chao, J. Zheng, H. Zhang, F. Li, F. Yan, Y. Tan, Z. Zhu, Chem. Eng. J. 2018, 281.
[15] J. Ran, G. Gao, F. T. Li, T. Y. Ma, A. Du, S. Z. Qiao, Nat. Commun. 2017, 13907.
[16] Y. Honda, H. Hagiwara, S. Ida, T. Ishihara, Angew. Chem. Int. Ed. 2016, 28, 8045.
[17] L. Li, J. Yan, T. Wang, Z. J. Zhao, J. Zhang, J. Gong, N. Guan, Nat. Commun. 2015, 5881.
[18] C. Xu, W. Yang, Q. Guo, D. Dai, M. Chen, X. Yang, J. Am. Chem. Soc. 2014, 2, 602.
[19] G. Liu, L. Ma, L.-C. Yin, G. Wan, H. Zhu, C. Zhen, Y. Yang, Y. Liang, J. Tan, H.-M. Cheng,
Joule 2018, 6, 1095.
[20] X. Zhou, E. M. Zolnhofer, N. T. Nguyen, N. Liu, K. Meyer, P. Schmuki, Angew. Chem. Int.
Ed. 2015, 45, 13385.
[21] F. Niu, S. Shen, L. Guo, J. Catal. 2016, 141.
[22] S. Mohajernia, S. Hejazi, A. Mazare, N.T. Nguyen, P. Schmuki, Chem. Eur. J. 2017,
23,12406.
[23] J. Saavedra, H. A. Doan, C.J. Pursell, L.C. Grabow, B.D. Chandler, Science, 2014, 345.
[24] Z. Liu, Z. Yin, C. Cox, M. Bosman, X. Qian, N. Li, H. Zhao, Y. Du, J. Li, D.G. Nocera, Sci.
Adv. 2016; 2 : e1501425
[25] J. C. Serrano-Ruiz, R. Luque, A. Sepulveda-Escribano, Chem. Soc. Rev. 2011, 11, 5266.
9
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
[26] F. Frusteri, L. Spadaro, C. Beatrice, C. Guido, Chem. Eng. J. 2007, 1-3, 239.
[27] F.A.J. Meskens, Synthesis 1981, 7, 501.
[28] M.R. Capeletti, L. Balzanob, G. Puente, M. Laborde, U. Sedran, Appl. Catal. A: Gen. 2000,
198, L1.
[29] K. Bonhoff, F. Obenaus, Pat. DE, 1980, 411.
[30] K. Oppenlaender, F. Merger, R. Strickler, F. Hovemann, H. Schmidt, K. Starke, K. Stork, W.
Vodrazka, Eur. Pat., 1980, 922.
[31] H. Zhang, Y. Wu, L. Li, Z. Zhu, ChemSusChem 2015, 7, 1226.
[32] T. W. Green, Protective Groups in Organic Synthesis Wiley, New York,1981.
[33] R. Morrison, R. Boyd, Organic chemistry, 4th ed., Allyn and Bacon, London, 1983.
[34] Y. Chao, J. Lai, Y. Yang, P. Zhou, Y. Zhang, Z. Mu, S. Li, J. Zheng, Z. Zhu, Y. Tan, Catal.
Sci. Technol. 2018, 13, 3372.
[35] H. Zhang, Z. Zhu, Y. Wu, T. Zhao, L. Li, Green. Chem. 2014, 9, 4076.
[36] H. Zhang, W. Zhang, M. Zhao, P. Yang, Z. Zhu, Chem. Commun. 2017, 9, 1518.
[37] B. Weng; Q. Quan; Y.-J. Xu, J. Mater. Chem. A 2016, 47, 18366.
[38] J. S. Jang, U. A. Joshi, J. S. Lee, J. Phys. Chem. C 2007, 111, 13280.
[39] B. Han, S. Liu, N. Zhang, Y.-J. Xu, Z.-R. Tang, Appl. Catal. B: Environ. 2017, 298.
[40] S. Cao, Y. Chen, C.-C. Hou, X.-J. Lv, W.-F. Fu, J. Mater. Chem. A 2015, 11, 6096.
[41] H. Park, D. A. Reddy, Y. Kim, S. Lee, R. Ma, T. K. Kim, Chemistry 2017, 53, 13112.
[42] Y. Chao, J. Zheng, J. Chen, Z. Wang, S. Jia, H. Zhang, Z. Zhu, Catal. Sci. Technol. 2017, 13,
2798.
[43] W. Lai, Z. Chen, J. Zhu, L. Yang, J. Zheng, X. Yi, W. Fang, Nanoscale 2016, 6, 3823.
[44] Z. Yang, D. Gao, J. Zhang, Q. Xu, S. Shi, K. Tao, D. Xue, Nanoscale 2015, 2, 650.
[45] W. Park, J. Baik, T.-Y. Kim, K. Cho, W.-K. Hong, H.-J. Shin, T. Lee, ACS Nano, 2014, 8,
4961.
[46] T. Simon, N. Bouchonville, M. J. Berr, A. Vaneski, A. Adrovic, D. Volbers, R. Wyrwich, M.
Doblinger, A. S. Susha, A. L. Rogach, F. Jackel, J. K. Stolarczyk, J. Feldmann, Nat. Mater. 2014, 11,
1013.
[47] H. Lu, J. Zhao, L. Li, L. Gong, J. Zheng, L. Zhang, Z. Wang, J. Zhang, Z. Zhu, Energy
Environ. Sci., 2011, 4, 3384.
[48]
P. Yang, J. Zhao, B. Cao, L. Li, Z. Wang, X. Tian, S. Jia, Z. Zhu, ChemCatChem, 2015,
7,2384.
10
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
a
b
500nm
500nm
c
d
(0.34nm)
CdS
(0.64nm)
NiMoS
200nm
5nm
Figure 1. (a) Typical SEM image of blank CdS nanorods, (b) SEM images of as-prepared samples
CdS/NiMoS-7 nanostructure. (b) and (d) TEM and HRTEM images of as-prepared CdS/NiMoS-7
nanostructure.
11
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
a
b
52.1
50
40
30
20
10
0
47.5
40.6
38.4
31.8
22.6
7
10
12
2
5
1
Loading amount of Ni-MoS2 (wt%)
180
150
120
90
60
30
0
0
2
4
6
8
10 12 14 16
Time (h)
Figure 2. (a) The rates of photocatalytic ethanol dehydrogenation over CdS/Ni-MoS2 samples with
different Ni-MoS2 loading amounts (c(H+) = 40 mM), (b) Photocatalytic ethanol dehydrogenation
cycling test (evacuation every 4 h) for CdS/NMS7 samples under visible-light (λ > 420 nm, 300 W
Xe lamp).
12
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
a
b
50
40
30
20
10
0
0
0.5 1.0 1.5 2.0 2.5 3.0
Concentration of H+ (x10-2 mol/L)
100
80
60
40
20
0
0.5
1.0
1.5
2.0
2.5
3.0
Concentration of H+ (x10-2 mol/L)
Figure 3. (a) The rates of photocatalytic ethanol dehydrogenation at different H+ concentration, (b)
The effect of H+ concentration on selectivity of DEE.
13
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
3480
3500
3520
3540
3560
Magnetic (G)
Figure 4. In-situ ESR spectrum in the process of ethanol degydrogenation over CdS/NMS7 catalyst
in the presence of DMPO (a spin-trapping agent) under visible light irradiation (30 mM H+).
14
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
a
b
CdS
CdS/NMS2
CdS-NMS7
CdS-NMS10
500
550
600
650
700
Wavelength (nm)
40
CdS
CdS/NMS2
CdS/NMS7
CdS/NMS10
30
20
10
0
80
100 120 140 160 180 200
Time (s)
Figure 5. (a) Transient photocurrent responses and (b) photoluminescence spectra with an excitation
wavelength of 420 nm of the as-prepared photocatalysts samples.
15
This article is protected by copyright. All rights reserved.

10.1002/chem.201804664
Chemistry - A European Journal
The table of contents entry
Photocatalytic ethanol dehydrogenation-acetalization to prepare value-added 1,1-dimethoxymethane
and H2 was achieved over non-precious metal CdS/Ni-MoS2 catalytic under visible light. This work
provides a promising strategy for atomic green economy application of bio-ethanol.
Keyword: visible light; non-precious metals; ethanol; photocatalytic; 1,1-diethoxyethane.
Yuguang Chao, Wenqin Zhang, Xuemei Wu, Nana Gong, Zhihong Bi, Yunqin Li, Jianfeng Zheng,*
Zhenping Zhu and Yisheng Tan*
Visible light Direct Conversion of Ethanol to 1,1-Diethoxyethane and Hydrogen over Non-
Precious Metal Photocatalyst
H2
CH3
H
H
C-H
2H+
Ni-MoS2
O
O
e-
H+
h+
CH3-C-H
DEE
e- / h+
CH3CH2OH
16
This article is protected by copyright. All rights reserved.