Studies On Catalyst Of Steam Reforming Of Methane For DIR-MCFC

As a high temperature fuel cell, MCFC's working temperature is about 650℃and the desulphurization gas or natural gas can became its raw material. In MCFC, Ni is the main electrode catalyst, but not noble metal catalyst. It always has high heat utilization.Based on so many advantages, MCFC is considered to have a good market prospect. DIR-MCFC is combined MCFC with steam reform methane (SRM)'s technical. The water from electrochemical reaction is the material of SRM; the H₂ from SRM is the material of electrochemical reaction. At the same time, the heat of electrochemical reaction can provide the reaction of SRM. That means MCFC can achieved the double coupling of material and energy. So it has not only important theory value but also practical application. According to these, it's important and necessary to develop catalysts that have high activity, stability and resistant carbon deposition at the operation of low temperature and steam carbon ratio.In this article, Ni was used as active component,γ-Al₂O₃ as support, Ni/γ-Al₂O₃ catalysts were prepared by incipient wetness impregnation method. It also studied the influence of different preparation method and different additive concentration on catalyst properties.. The experimental results indicate that the Ni/γ-Al₂O₃ had good catalytic activity at the conditions of the temperature of 650℃, S/C=2:1, CH₄ space velocity of 20ml/g(cat)·min. When the concentration of Ni is 25%, CH₄ conversion keeps at 62.46%, H₂ yield is 77.72%. Both La and Ce can improve catalytic activity effectively. Preparing method had major effect, the performance order of the catalyst is: impregnation Ni in advance and then impregnation additive>Ni and additive blend together impregnation>impregnation additive in advance and impregnation Ni later. The result also showed that the 25%Ni+3%La catalyst had the best performance: methane conversion was 71.69 %> H₂ yield was 76.9% and CO selectivity was 61%. From the result, It can be obtained that La had more effect on improving CH₄ conservation and CO selectivity. The catalyst had high stability and activity, there wasn't performance reduce obviously after 30 hours reaction.