Mg-Vacancies Induced Ni-Vacancy Clusters: Highly Efficient Hydrogen Production from Cellulose

H2 production from aqueous phase reforming (APR) is of great importance but desires much more enhancement of H2 production efficiency. Our previous work reported a catalytic H2 production over metal oxide (MMO) supported Ni derived from Ni-containing layered double hydroxides (Ni-MgAl-LDHs). Here we report a catalytic H2 production from APR of cellulose over MMO supported defects-rich Ni derived from Ni-MgAl-LDHs with abundant Mg (II) vacancies (VMg). The VMg well retained in the calcination under H2 atmosphere induces the formation of Ni vacancies not only at Ni-MMO interface but also on the surface of Ni particles. A H2 yield of up to 70.4 % has been achieved from APR of cellulose over the defects-rich Ni-MMO, which is almost 2.5 times of the H2 yield from APR of cellulose reported till now (~ 30 %). A combined investigation by quasi in situ XPS, EPR, PAS, and in situ FT-IR verifies that Mg vacancies on the support surface facilitate the cleavage of C-H bond, while Ni vacancies on the Ni particles boost the breakage of C-C bond.