Angelw. Chem. Int. ed.: the research team of fan Weibin, National Key Laboratory of coal transformation, Shanxi Institute of coal and chemical technology, has made important progress in the research of Cu based catalysts

Copper based catalyst It has been widely used in many important chemical reaction processes, including syngas conversion, Co / hydrocarbon selective oxidation, methanol steam reforming, water gas change, ester / aldehyde / acid hydrogenation and alcohol dehydrogenation, etc Therefore, it has attracted the general attention of researchers However, the catalytic mechanism and reaction path of Cu0 and Cu + species are still unclear, so it is a big challenge to solve this problem The reason is copper Species are unstable in structure and chemistry, and the aggregation and growth of particles and the dynamic change of valence state often occur in the reaction process Recently, fan Weibin, a research team from the State Key Laboratory of coal transformation of Shanxi Institute of coal and chemical technology, designed and prepared a highly stable Cu @ mesoporous silica core-shell structure catalyst (Figure 1a-d) After the deactivation of the catalyst, the catalytic performance of the catalyst was completely recovered after 6 h of calcination at 550 OC in air (Fig 1E), and the morphology and size of Cu particles did not change significantly It is possible to study the catalytic mechanism of copper species Source: angelw Chem Int ed, 2018, DOI: 10.1002/anie.201710605 considering that the dehydrogenation of methanol to methyl formate is a typical C1 reaction, which involves not only the breaking of O-H and C-H bonds, but also the by-products CO and CO2 The research team took this reaction as a model reaction, combined with in-situ XAFS / XPS / IR spectrum, isotope labeling experiment and quantitative calculation, revealed the active species of methanol dehydrogenation reaction, deeply understood the reaction induction period, and clarified the catalytic mechanism and reaction path of Cu0 and Cu + species (Figure 2) It was found that Cu0 first promoted the O-H bond activation fracture of methanol molecules to form CH3O species, and then promoted the C-H bond activation fracture to form HCHO intermediate The two species then reacted at Cu0 site to form h2cooch3 intermediate product, which was further dehydrogenated to methyl formate The rapid control step in the process was the C-H bond fracture of CH3O species to form HCHO intermediate Cu + can not catalyze the cleavage of O-H and C-H bonds of methanol, but can rapidly decompose HCHO intermediates into CO and H 2 In the early stage of the reaction (induction stage), CH3O species are rapidly generated and strongly adsorbed on the Cu0 site by oxygen atoms, causing some Cu0 species to oxidize rapidly to Cu +, greatly reducing the initial reaction activity; as the reaction proceeds, the concentration of HCHO intermediate increases, the consumption rate of CH3O species increases, and some Cu0 adsorbing CH3O species increases The site was "released" to improve the reactivity (Fig 2a, b); when the production and consumption of CH3O species reached a balance, the induction period ended and entered a stable period Source: angelw Chem Int ed., 2018, DOI: 10.1002/anie.201710605 the research was supported by NSFC, science foundation of Shanxi Province, talent science and technology innovation project of Shanxi Province and CAS / SAFEA innovation team international cooperation program Related work published in angew Chem Int ed., 2018, DOI: 10.1002/anie.201710605 paper link: https://doi.org/10.1002/anie.201710605 brief introduction of researcher fan Weibin: http://sourcedb.sxicc.cas.cn/zw/zjrc/200907/t20090704 researcher fan Weibin 1930370.html