Al-Si@Al_2O_3核壳结构载体的制备及其催化应用

Preparation and catalytic application Al-Si@Al_2O_3 core-shell structured carrier

以微米级铝硅(Al-Si)合金粉为原料,采用简单的水热反应,设计开发出一种以鳞片状Al_2O_3为壳、Al-Si合金为核的催化剂载体(Al-Si@Al_2O_3).通过傅里叶红外分析(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)及透射电镜(TEM)等表征分析表明,经过水热反应后,Al-Si合金表面原位生成片状的AlOOH,内核为未反应的Al-Si合金,500℃煅烧后浸渍载Pd制备出Pd/Al-Si@Al_2O_3催化剂,活性组分Pd粒子均匀分散在载体表面.以苯乙烯加氢为探针反应考察Al-Si合金原料的粒径、铝含量等因素对所制备催化剂性能的影响,同时还与水浴、碱处理及酸处理所制备的载体和传统载体活性炭、活性氧化铝进行比较.结果表明,在水热条件下,以粒径为5μm、铝含量为88%的Al-Si合金粉为原料制备的Pd/Al-Si@Al_2O_3具有较优的催化性能,且其催化活性优于活性炭和活性氧化铝载Pd催化剂.

A simple hydrothermal method using micron level Al-Si alloy powder to prepare a novel core-shell structured catalytic carrier（Al-Si@Al2O3）, with a shell of flaky Al2O3 layer and a core of Al-Si alloy was reported. The analysis of FT-IR, XRD, SEM and TEM show that a nano-flaky Al OOH layer in situ grew on the surface of Al-Si alloy with an unreacted core via a hydrothermal process. And then after a 500 ℃ sintering process, the Pd/Al-Si@Al2O3 catalyst with highly dispersed Pd nanoparticles was prepared by immersion method. The effects of the size and Al content of Al-Si alloy on the prepared catalysts for styrene hydrogenation performance were researched. Meanwhile, water bath, alkali and acid treated Al-Si alloy as catalytic supports were compared, as well as traditional activated carbon and alumina. The results show that the Pd/Al-Si@Al2O3catalyst has a better styrene hydrogenation performance when prepared using 5 μm and 88 %content of aluminum via hydrothermal method. It has higher catalytic activity than that of activated carbon and alumina supports.