629-11-8Relevant articles and documents
Determining Roles of Cu0 in the Chemosynthesis of Diols via Condensed Diester Hydrogenation on Cu/SiO2 Catalyst
Wang, Weichao,Wang, Hui,Zhang, Jingwei,Kong, Lingxin,Huang, Huijiang,Liu, Wei,Wang, Shengping,Ma, Xinbin,Zhao, Yujun
, p. 3849 - 3852 (2020)
Copper-based catalyst was applied in the condensed diester hydrogenation with unexpected high selectivity (~100 percent) to 1,6-hexanediol. On basis of the mass transfer analysis and kinetics results, the reaction rate of the condensed diester hydrogenation was deduced to be controlled by the activation of hydrogen on Cu0 sites, which was further demonstrated by the correlations between the catalytic activity and different copper species. Importantly, this catalysis mechanism is different with that of gas-phase diester hydrogenation, which is generally determined by the adsorption of ester on Cu+ species.
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Raphael,Roxburgh
, p. 3875 (1952)
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Synthesis of Supported RhMo and PtMo Bimetallic Catalysts by Controlled Surface Reactions
Alba-Rubio, Ana C.,Sener, Canan,Hakim, Sikander H.,Gostanian, Thomas M.,Dumesic, James A.
, p. 3881 - 3886 (2015)
We previously described a synthesis method to prepare bimetallic catalysts with narrow nanoparticle size and composition distributions by means of controlled surface reactions (CSR) between a reduced supported metal nanoparticle and an organometallic precursor of an oxophilic promoter metal. Herein, we report a comparison of such catalysts with those prepared by traditional incipient wetness impregnation. STEM/EDS analysis indicates that catalysts prepared by CSR exhibit more effective interaction of metals, thereby minimizing the undesirable formation of component-rich nanoparticles and/or monometallic domains. Reaction kinetics studies using these bimetallic catalysts reveal that optimal conversion rates in a selective CO hydrogenolysis reaction (i.e., hydrogenolysis of 2-(hydroxymethyl)tetrahydropyran to 1,6-hexanediol) could be achieved using a lower amount of the oxophilic promoter metal for the catalysts prepared by the CSR approach, as compared to their impregnated counterparts. A superior method for greater results: At the same conversion rate level, catalysts prepared by controlled surface reactions (CSR) requires smaller amount of promoter as compared to those prepared by incipient wetness impregnation (IWI). This increased performance is attributed to the uniform bimetallic composition of the catalysts prepared by CSR.
Reductive depolymerization of polyesters and polycarbonates with hydroboranes by using a lanthanum(iii) tris(amide) catalyst
Berthet, Jean-Claude,Cantat, Thibault,Kobylarski, Marie
supporting information, p. 2830 - 2833 (2022/03/09)
The homogeneous reductive depolymerization of polyesters and polycarbonates with hydroboranes is achieved with the use of an f-metal complex catalyst. These polymeric materials are transformed into their value-added alcohol equivalents. Catalysis proceeds readily, under mild conditions, with La[N(SiMe3)2]3 (1 mol%) and pinacolborane (HBpin) and shows high selectivity towards alcohols and diols, after hydrolysis.
MOF-derived hcp-Co nanoparticles encapsulated in ultrathin graphene for carboxylic acids hydrogenation to alcohols
Dong, Mei,Fan, Weibin,Gao, Xiaoqing,Zhu, Shanhui
, p. 201 - 211 (2021/06/03)
Highly efficient conversion of carboxylic acids to valuable alcohols is a great challenge for easily corroded non-noble metal catalysts. Here, a series of few-layer graphene encapsulated metastable hexagonal closed-packed (hcp) Co nanoparticles were fabricated by reductive pyrolysis of metal-organic framework precursor. The sample pyrolyzed at 400 °C (hcp-Co@G400) presented outstanding performance and stability for converting a variety of functional carboxylic acids and its turnover frequency was one magnitude higher than that of conventional facc-centered cubic (fcc) Co catalysts. In situ DRIFTS spectroscopy of model reaction acetic acid hydrogenation and DFT calculation results confirm that carboxylic acid initially undergoes dehydroxylation to RCH2CO* followed by consecutive hydrogenation to RCH2CH2OH through RCH2COH*. Acetic acid prefers to vertically adsorb at hcp-Co (0 0 2) facet with a much lower adsorption energy than parallel adsorption at fcc-Co (1 1 1) surface, which plays a key role in decreasing the activation barrier of the rate-determining step of acetic acid dehydroxylation.