Mg-vacancy-induced Ni-vacancy clusters: highly efficient hydrogen production from cellulose

Abstract

H₂ production from aqueous phase reforming (APR) is of great importance, but an enhancement in the H₂ production efficiency is required. Our previous work reported the catalytic production of H₂ over metal oxide (MMO)-supported Ni derived from Ni-containing layered double hydroxides (Ni-MgAl-LDHs). Herein, we report the catalytic production of H₂ from APR of cellulose over MMO-supported defect-rich Ni derived from Ni-MgAl-LDHs with abundant Mg(II) vacancies (V_Mg). The well-retained V_Mg during calcination under an H₂ atmosphere induced the formation of Ni vacancies not only at the Ni–MMO interface, but also on the surface of the Ni particles. An H₂ yield of up to 70.4% was achieved via the APR of cellulose over the defect-rich Ni–MMO, which is almost 2.5 times that from the APR of cellulose reported to date (∼30%). A combined investigation via quasi in situ XPS, EPR, PAS, and in situ FT-IR verified that the Mg vacancies on the support surface facilitate the cleavage of the C–H bond, while the Ni vacancies on the Ni particles boost the breakage of the C–C bond.