Catalysis Today, Vol.293, 113-121, 2017
Enhanced catalytic performance of Pt/TiO2 catalyst in water gas shift reaction by incorporation of PRGO
TiO2 over partially reduced graphite oxide (PRGO) was prepared using the hydrothermal synthesis method with varying amounts of the TiO2 precursor for WGS catalyst support. Pt catalysts for the low temperature water gas shift (WGS) reaction were then prepared by the incipient wetness impregnation method with the TiO2/PRGO (TirGO) supports. The WGS reaction was carried out with the Pt/TiO2/PRGO (Pt/TirGO) catalysts to investigate the effect of the incorporation of PRGO on the catalytic activity. Characterization of the supports and catalysts was performed with XRD, SEM, XPS, Raman spectroscopy, BET surface analysis, and temperature-programmed reduction (TPR). It was found that functional groups containing oxygen on the PRGO provide anchoring sites for the TiO2 precursors during the hydrothermal process, resulting in enhanced catalytic activity. In addition, the introduction of PRGO also improved the reducibility of the catalysts. It was also confirmed that there exists an optimal ratio of TiO2 to PRGO that facilitates a uniform dispersion of nanosized TiO2 on the PRGO by balancing the number of functional groups on PRGO with the amount of TiO2 precursor used. Among the Pt/TirGO catalysts synthesized, Pt/TirGO-5 possessed the optimum ratio of TiO2 to PRGO and showed excellent catalytic activity in the WGS reaction, achieving over 80% conversion of CO at the low temperature of 280 degrees C and a very high gas hourly space velocity (GHSV) of 47,700h(-1). (C) 2016 Elsevier B.V. All rights reserved.