Effect of Ni-Co bimetallic core-shell catalyst for coke resistance in CO2 reforming of biomass Tar

Abstract

The deactivation of catalysts due to coke deposition is a major challenge in CO2 reforming of tar technology. The Ni-Co bimetallic catalysts have good resistance to coke deposition for steam reforming of tar, but the performance of for filamentous coking of CO2 reforming of tar is not known. In this work, the effect of Ni-Co bimetallic synergy on the corrosion resistance of filamentous coke was investigated by comparing the catalytic performance of nickel monometallic and Ni-Co bimetallic core-shell catalysts. The Ni8Co@SiO2 catalyst showed efficient and stable hydrogen conversion (62.3–53.3%) and carbon conversion (64.7–56.7%) and excellent resistance to coke deposition with little coke (1.5%) deposition after 300 min of CO2 reforming tar reaction. The Ni8Co@SiO2 was also regenerated for four cycles, demonstrating excellent catalytic activity and recyclability performance. However, as the cobalt content in the Ni-Co bimetal increased, the activity and resistance to coke deposition of the core-shell catalyst decreased due to the increase in size of the Ni-Co alloy and the decrease in the nickel active component. The above results are helpful for the future application of bimetallic core-shell catalyst during CO2 reforming tar.