Carbon Monoxide Oxidation over rGO-Mediated Gold/Cobalt Oxide Catalysts with Strong Metal–Support Interaction
Shaohua Xie, Yuxi Liu, Jiguang Deng, Jun Yang, Xingtian Zhao, Zhuo Han, Kunfeng Zhang, Yue Lu, Fudong Liu, Hongxing Dai
Abstract
The strong interaction between Au nanoparticles and support (Au–metal oxide interface) usually governs the performance of a supported Au catalyst in heterogeneous catalysis. In this study, a series of Au/reduced graphene oxide (rGO)/three-dimensionally ordered macroporous (3DOM) Co3O4 catalysts with similar textural properties were prepared using the poly(methyl methacrylate)-templating and poly(vinyl alcohol)-protected reduction strategies. It was found that introducing reduced graphene oxide (rGO) as an electron-transfer bridge between Au and 3DOM Co3O4 could significantly strengthen the strong metal–support interaction (SMSI), thus enhancing the catalytic activity for CO oxidation. Among all of the catalysts, 1.86 wt % Au/2 wt % rGO/3DOM Co3O4 (1.86Au/2rGO/3DOM Co3O4) showed the highest catalytic activity: the CO reaction rate at 40 °C (432.8 μmol/(gAu s)) was 2 times higher than that (208.2 μmol/(gAu s)) over 1.87Au/3DOM Co3O4. The introduction of rGO could improve the activation of oxygen molecules and hence increase the low-temperature catalytic activity. The strategy for strengthening the SMSI via rGO mediation would guide the designing of highly efficient supported metal catalysts for low-temperature oxidation of CO.