Noble-metal-free and Pt nanoparticles-loaded, mesoporous oxides as efficient catalysts for CO2 hydrogenation and dry reforming with methane.

• Series of free-standing as well as controlled size Pt nanoparticles-loaded mesoporous metal oxides. • Pt-free NiO exhibited the highest catalytic activity and showing 100% CH 4 selectivity. • Striking catalytic properties can be ascribed to the presence of metallic Ni and the optimal dynamics of Ni/NiO x structure. In this study, a series of free-standing as well as controlled size Pt nanoparticles-loaded mesoporous metal oxides (NiO, Co 3 O 4, CeO 2 and MnO 2) with high surface area and designed pore structure were prepared by hard template method and used as catalysts for CO 2 hydrogenation together with dry reforming of CO 2 with methane. The physicochemical properties of catalysts were analysed by N 2 adsorption-desorption isotherm, XRD, TEM, and H 2 -TPR. Pt-free and Pt-loaded mesoporous NiO and Co 3 O 4 performed with high catalytic activity and selectivity for both CO 2 activation reactions. Pt-free NiO exhibited the highest catalytic activity and also showing 100% CH 4 selectivity between 473–673 K and ˜1:1 H 2 /CO 2 ratio between 673–973 K in CO 2 hydrogenation and dry reforming with methane, respectively. The enhanced catalytic properties can be due to the existence of metallic Ni as well as the optimal dynamics of Ni/NiO x structure under reaction conditions. [ABSTRACT FROM AUTHOR]