Pillared clay-supported gold catalysts for CO oxidation

Abstract

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.