Co-based nano-catalyst for hydrogen production by ethanol steam reforming and preparation method thereof

Abstract

The invention discloses a Co-based nano-catalyst for hydrogen production by ethanol steam reforming and a preparation method thereof. The catalyst is made by taking nanoporous silicon dioxide aerogel as a catalyst carrier, a metal elementary substance cobalt nanowire as an active component, and CeO2 nano-particles and ZnO nano-particles as adjuvants. The preparation method comprises the following steps: preparing a sol from silanolate, an alcohol solvent, cobalt nitrate and zinc nitrate, cerous nitrate and an acidic catalyst at certain proportions; forming a wet gel complex, and then performing supercritical fluid drying. The catalyst has strong catalytic activity and selectivity for the hydrogen production by the ethanol steam reforming, has higher hydrogen yield and stronger CO2 selectivity at a lower temperature, limits the selectivity of byproducts CH4 and CO at a lower level, and has good deactivation resistance and stability. Meanwhile, the preparation method has simple process, low cost and certain mechanical strength.

Description

technical field [0001] The invention belongs to the technical field of catalyst materials for hydrogen production by ethanol steam reforming of liquid fuel used in fuel cells, and relates to a cobalt-based catalyst for hydrogen production by ethanol steam reforming and a preparation method thereof, in particular to a silicon dioxide gas condensation Cobalt-based nano catalyst material with gel as catalyst carrier and preparation method thereof. Background technique [0002] Fuel cells directly and efficiently convert the chemical energy stored in fuel and oxidant into electrical energy. High-purity, non-toxic hydrogen is an ideal fuel for fuel cells. Currently, liquid fuel reforming is a better way to produce hydrogen. [0003] Ethanol is a renewable resource, non-toxic, and does not contain sulfur that is likely to poison the platinum electrodes of fuel cells. It is an environmentally friendly fuel suitable for hydrogen production. Ethanol steam reforming is an important...

AI Technical Summary

Problems solved by technology

This type of catalyst has high ethanol conversion and hydrogen production effect, but due to the catalyst carrier Al 2 o 3 The acidity of the catalyst leads to serious carbon deposition and poor stability

Furthermore, CH on Ni-based catalysts 4 and the formation of CO is relatively large, CH 4 Competing for hydrogen atoms, CO poisons the fuel cell's Pt electrodes, both undesired by-products

[0007] Among the cobalt-based catalysts, the Co / ZnO catalyst has the best performance, high selectivity and low conversion temperature, and the selectivity is very high. The CH in the reaction gas 4 The content is less than 3%, the CO content is very low, but there are easy inactivation and stability problems

[0008] At present, cobalt-based non-noble metal catalysts are mainly prepared by impregnation method and co-precipitation method. Although the preparation process is simple, it is difficult to obtain a catalyst with high specific surface area, high dispersion and uniform dispersion, and it is difficult to solve the problem of catalytic deactivation.

In addition, the catalytic activity and selectivity of ethanol steam reforming reaction need to be further improved

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