Zinc-modified copper-based catalyst for hydrogen production by steam reforming of dimethyl ether and preparation method thereof

Abstract

The invention relates to a zinc modified copper-based catalyst for hydrogen production by dimethyl ether steam reforming and a preparation method. The catalyst is prepared from CuO-ZnO-SiO2 / gamma-Al2O3. The mass ratio of CuO-ZnO-SiO2 to gamma-Al2O3 is (2 to 5): 1. The mass percentages of CuO, ZnO and SiO2 in CuO-ZnO-SiO2 are respectively 23 to 28 percent, 5 to 23 percent and 54 to 67 percent. The catalyst is prepared by two steps of ammonia evaporation and immersing. Regulation of the content of generated cupric silicate is realized by changing conditions such as the concentration of an amino-copper solution, the pH value, the stirring time and the ammonia evaporation temperature, and elemental zinc is introduced to modify the catalyst. The catalyst is applied to the field of hydrogen production reaction by dimethyl ether steam reforming in a fixed bed for the first time; furthermore, by the adding of the elemental zinc, carbon monoxide which is a byproduct is low in selectivity, and the hydrogen yield is high; the catalyst is high in thermal stability.

Description

technical field [0001] The invention relates to a catalyst for hydrogen production by steam reforming of dimethyl ether and a preparation method. The invention belongs to the technical field of hydrogen production by steam reforming of dimethyl ether. The novel catalyst has the advantages of high reactivity, low selectivity of by-product carbon monoxide, high stability and the like. Background technique [0002] In recent years, the situation of energy shortage has become more and more serious. The use of fossil energy not only makes people face a serious energy crisis, but also has a bad impact on the environment on which human beings live. People's demand for energy has gradually shifted to new energy sources. The development of proton exchange membrane fuel cells (PEMFCs) fueled by high-purity hydrogen provides ideas for increasingly tight energy demands. However, since hydrogen is difficult to store and transport, it is necessary to develop an in situ hydrogen produc...

AI Technical Summary

Problems solved by technology

CN103223343A reported X / CuZnAl / γ-Al 2 o 3 (X is one of Li, Na, K, Rb) is used for hydrogen production by steam reforming of dimethyl ether, but the catalyst is not stable and is easily deactivated at higher temperatures

CN101822993A uses supported phosphotungstic acid catalyst and Cu / ZnO / Al 2 o 3 Commercial catalysts are compounded to make bifunctional catalysts for hydrogen production by steam reforming of dimethyl ether. The resulting product has high selectivity, but the conversion rate of dimethyl ether is low

US7241718 discloses adopting sol-gel method to prepare a series of Cu and at least one other metal (Mn, Fe, Zn, etc.) and active alumina mechanically mixed as dimethyl ether steam reforming hydrogen production catalyst, its preparation method is loaded down with trivial details and Preparation conditions are not easy to control

It can be seen that Cu-based catalysts have high DME reforming activity and good selectivity and are used as metal active components for methanol steam reforming, but copper species are easily deactivated by sintering at higher reaction temperatures.

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