甲烷蒸汽重整反应中表面修饰载体对Ni基催化剂抗氧化性能的影响

Effect of Surface Modified Supports on Resistance to Oxidation of Ni Catalysts in Reaction of Methane Steam Reforming

在甲烷蒸汽重整反应中,Ni基催化剂在高温下生成NiAl2O4尖晶石是催化剂失活的一个重要原因。本实验利用单层分散负载耐高温ZrO2作载体表面修饰,再浸渍Ni制备成催化剂。经过900℃或1200℃的高温焙烧后,利用甲烷蒸汽重整反应的活性实验和催化剂表征考察载体表面修饰对催化剂抗氧化能力的影响。结果表明,载体表面修饰的催化剂具有较好的抗氧化能力,特别是掺杂Y2O3的ZrO2修饰在载体上具有更好的抗氧化能力。

It is an important reason of catalyst deactivation that Ni-based catalysts generate NiAl2O4 spinel at high temperature in reaction of methane steam reforming (MSR). The present work intended to synthesize the Ni-based catalysts by the wet impregnation on the supports surface modified with ZrO2 or rare earth oxides. After calcined at as high as 900℃ or 1200℃, the prepared catalysts were also characterized by the XRD, H2-TPR techniques and catalyst activity experiments. The results showed that the surface modified by material of Zr and rare earth elements could lead to the formation of MgAl2O4, ZrAlO or Zr(Al2O4)2 species, which inhibited the interaction of Ni with Al2O3 to form NiAl2O4 spinel. Therefore the high-temperature stability of Ni catalysts was improved.