CH_4-CO_2重整制合成气Ni基催化剂的失活研究

Studies on the mechanism of deactivation of Ni based catalysts for CH 4 CO 2 reforming to syngas

ＣＨ４－ＣＯ２重整制合成气反应（ＭＣＲ）中导致Ｎｉ基催化剂失活的主要原因可能有二：一是助剂组份碳酸化生成稳定碳酸盐物种毒化了反应活性位；二是笼状（包括石墨态和无定型态）炭的沉积覆盖了催化剂表面。ＭＣＲ反应中炭的沉积主要有两种形式：一是以须状形式进行堆集，二是以笼状形式覆盖于催化剂表面，前者对于催化剂活性的保持似无明显影响，后者则是导致催化剂失活的主要原因之一。

The Mechanism of deactivation of Ni based catalyst for methane carbon dioxide reforming(MCR) to syngas has been studied by means of XRD and TEM techniques and several designed experiments carried out.The results indicate that the formation of stable carbonate species due to carbonation of the catalyst and the deposition of encapsulated carbon on the surface of the catalyst may lead to the loss of catalyst activity,especially the latter.The whisker carbon,which may also form on the surface of the catalyst,seems to have no obvious effect on the Ni based catalyst keeping active for relatively long time.