Cu-Ni Nanocatalysts in Mesoporous MCM-41 and TiO 2 to Produce Hydrogen for Fuel Cells via Steam Reforming Reactions

Abstract

We have synthesized mesoporous SiO 2 (MCM-41) and TiO 2 encapsulated bimetallic Cu-Ni nanocatalysts using an optimized one-pot hydrothermal procedure. The catalysts were characterized using BET, XRD, TGA-DSC and HRTEM techniques. While bimetallic Cu-Ni/MCM-41catalysts have high surface area- 634-1000 m 2 /g, Cu-Ni/TiO 2 yields surface area of 250-350 m 2 /g depending on the metal loading (5-10 wt%). The XRD studies confirmed a long range ordered structure in Cu-Ni/MCM-41 and the presence of the catalytically active anatase phase in the crystalline Cu-Ni/TiO 2 . The results from HRTEM studies were consistent with the mesoporosity of both supports. These catalysts were tested for methanol conversion and H 2 /CO selectivity via steam reforming of methanol (SRM) reactions in a fixed bed reactor. There is a distinct difference in the performance of these two supports. Bimetallic 3.33%Cu6.67%Ni/TiO 2 catalyst showed an impressive 99% H 2 selectivity at as low as 150°C and a maximum conversion of 92% at 250 °C but 3.33%Cu6.67%Ni/MCM-41 catalyst did not show any H 2 selectivity at 150°C and only ~12% conversion at 250°C. The effect of each support and relative metal loadings on the activity and selectivity of the SRM reaction products at different temperatures is discussed.