Catalyst for hydrogen production by self-heating reforming of methanol and preparation method thereof

Abstract

The invention discloses a catalyst for hydrogen production by self-heating reforming of methanol and a preparation method thereof, in particular relates to a catalyst for hydrogen production by self-heating reforming of methanol and using nanometer cerium, zirconium and aluminum composite oxide as a carrier and a preparation method thereof. The catalyst comprises transition metal composite oxide as an active ingredient, rare earth or / and alkaline earth metal oxide as a catalysis assistant, a porous material matrix and the nanometer cerium, zirconium and aluminum composite oxide as a carrier coating, wherein the mol ratio of Ce to Zr is 6:1-36, and the mol ratio of the sum of Ce and Zr to Al is 1-9:3; the coating amount of the nanometer cerium, zirconium and aluminum composite oxide is 10-70 percent of that of the porous material matrix by weight; and the particle diameter of the nanometer cerium, zirconium and aluminum composite oxide carrier is 5-20nm. The catalyst has the advantages of good activity, high strength, good heat stability, simple preparation technology and relatively low cost, does not need activation in advance before use, and can be repeatedly used without activity reduction.

Description

technical field [0001] The invention relates to a catalyst for hydrogen production by autothermal reforming of methanol and a preparation method thereof, in particular to a catalyst for hydrogen production by autothermal reforming of methanol with nano-cerium-zirconium-aluminum composite oxide as a carrier coating and a preparation method thereof. Background technique [0002] As countries around the world pay more and more attention to environmental pollution and energy crisis, the development of clean energy is getting more and more attention, especially the use of hydrogen energy as a new energy has become a research hotspot in various countries. In order to solve the storage, transportation, and refueling problems of hydrogen directly used as fuel, mobile hydrogen production technology has been extensively studied. Proton exchange membrane fuel cell (PEMFC) is most suitable as a mobile power source due to its low operating temperature, fast start-up, high operating curre...

AI Technical Summary

Problems solved by technology

Al 2 o 3 It is helpful for the dehydration of methanol to form ether, and the existence of ZnO is beneficial for the dehydrogenation of methanol, but the Cu catalyst has poor stability and low anti-toxic performance, especially in the autothermal reforming process due to the influence of methanol combustion. It is easy to sinter or deactivate due to carbon deposition. The modified catalyst still cannot meet the requirements of fuel cell hydrogen source. At the same time, the catalyst needs to be pre-activated before the reaction, and special passivation treatment is required when shutting down.

Another type of catalyst is a noble metal catalyst, represented by a Pd-Zn catalyst, such as the Pd-Zn-Ce-Zr catalyst in the patent US20010021469A1. The base catalyst is convenient, but the content of CO in the reformed gas gradually increases with the progress of the reaction, that is, the selectivity of CO becomes poor, and the amount of precious metals is large, and the high price greatly limits its application in this field

In recent years, studies have also shown that catalysts prepared with non-copper-based and non-noble metals as the main active components and composite oxides of rare earth metals and transition metals as transition layer additives have better activity, such as patent CN1305564C, but The preparation process of the catalyst is complicated, there are many processes, and a layer of aluminum glue needs to be pre-coated as a transition layer before coating the non-metallic carrier. According to the reported results, the CO content in the reformed tail gas is relatively high, and a small amount of methane is produced , when applied to the hydrogen source of the fuel cell, its high CO content makes the subsequent removal of CO need to go through the water vapor shift reaction, which increases the pressure of CO removal and increases the cost

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