Dragon fruit-like Pt-Cu@mSiO2 nanocomposite as an efficient catalyst for low-temperature ethanol steam reforming

Abstract

The critical problem facing catalysts for the LT-ESR is deactivation owing to sintering of the active metal and carbon deposition. To solve this problem, a dragon fruit-like Pt-Cu@mSiO2 catalyst for LT-ESR reaction has been successfully fabricated by a facile encapsulation strategy. Structural and morphological analysis shows that the Pt-Cu@mSiO2 nanocomposite (approximately 400 nm) has a uniform dragon fruit-like structure, with well crystallized Pt-Cu alloy nanoparticles (about 50 nm) embedded in the mSiO2. Benefiting from the unique components and architectural features, the dragon fruit-like Pt-Cu@mSiO2 nanocomposite with optimal Pt/Cu ratio present superior performance than that of Pt@mSiO2, Cu@mSiO2 and supported Pt-Cu/mSiO2 catalysts in terms of activity, H2 selectivity, and stability in the LT-ESR reaction. Moreover, the synergistic effect of platinum and copper can substantially decrease the CO concentration. It is crucial that the mesoporous SiO2 shell not only make the embedded Pt-Cu alloy nanoparticles easily accessible but also effectively prevent leaching and aggregation of active sites as well as spatially suppress the carbon deposition on the active surface, thus maintain a good catalytic activity during the 150 h stability test at 400 °C.