CeO2–Ni@SiO2 Catalyst with Shell-Mediated Diffusion in the Ni Membrane Reactor for Model Biomass-Derived Syngas Conversion

Abstract

Model biomass-derived syngas provides a controlled multicomponent feed for evaluating CH4 and CO2 conversion under conditions representative of the principal gaseous components of biomass gasification gas. In this study, an integrated catalytic membrane design was developed, in which a CeO2–Ni@SiO2 core–shell catalyst was incorporated into a dense H2-separating Ni membrane for the conversion of CH4 and CO2 in model biomass-derived syngas. The tailoring of the fine SiO2 shell not only improved the reducibility and accessibility of Ni active species but also mediated the mesoporous diffusion channel for controlled transport of gaseous reactants. Coupled with in situ H2 removal through the Ni membrane, the core–shell catalyst achieved CH4 and CO2 conversions of 91.6% and 52.8% at 750 °C, respectively, corresponding to increases of more than 50% and 25% compared with the fixed-bed counterpart. In addition, stable operation with negligible carbon deposition was maintained for approximately 200 h. This work demonstrates that the CeO2–Ni@SiO2 coupled Ni membrane reactor provides an effective strategy for the controlled conversion of model biomass-derived syngas and simultaneous H2 recovery.