Pillared clay-supported gold catalysts for CO oxidation

摘要

Gold supported on various bentonites was prepared using hydrothermal and co-precipitation methods. The catalysts were characterized by FT-IR, BET, XRD, TEM, SEM, XPS and ICP and tested for CO oxidation reaction. It was found that the Au-Al-Ce pillared bentonite, Au-Al-Ce/Na-LBen (CP) and Au-Al-Ce/Na-LBen (HT), have better catalytic activity and stability than Au/Na-Lben and Au/Al-Ce-Na-LBen. Characterization results show that gold nanoparticles could move into the interlayer spaces of bentonite, which contributes to the high stability of the Au-Al-Ce/Na-LBen (HT) and Au-Al-Ce/Na-LBen (CP) samples. Ce oxide is distributed on the surface of Au-Al-Ce/Na-LBen (HT), while it stays in the interlayers of the bentonite in the Au-Al-Ce/Na-LBen (CP) sample. The pillaring process could increase the d((001)) space of the bentonite since the Ce and Au species could move into the interlayer space of the bentonite. The acid-activation process clearly increases the surface area of the bentonite, while the pillaring process increases the surface area of the samples slightly.