Enhanced stability of Ni-CaO catalysts by perovskite-type stabilizer in biomass pyrolysis for hydrogen production

The bifunctional catalyst provided a novel platform for biomass pyrolysis to efficiently and cleanly produce hydrogen, realizing the high-value conversion of biomass. First, the effect of catalyst/biomass ratios on the reaction activity of the Mo0.5Ni1Ca7 catalyst was investigated. On this basis, the effects of La2O3 and LaCoO3 stabilizers on the cycling stability of the Mo0.5Ni1Ca7 catalyst were examined. Eventually, the catalytic mechanism and the anti-deactivation model of the Mo0.5Ni1Ca7-LaCoO3 catalyst were proposed in this paper. The results showed that the LaCoO3 perovskite-type stabilizer greatly enhanced the cycling stability of the catalyst. In particular, the H2 yield of the Mo0.5Ni1Ca7-LaCoO3 catalyst was slightly reduced from 402 mLg  1 biomass to 392.05 mLg  1 biomass after ten cycles, with a relative decrease of only 2.47%. After ten regeneration cycles, the Mo0.5Ni1Ca7- LaCoO3 catalyst maintained high oxygen activity, demonstrating that the catalyst exhibited stable coke resistance. The surface structure of the catalyst was optimized after ten cycles with the formation of more fine particles, which allowed the catalyst to maintain a high activity. The excellent dispersion of the LaCoO3 stabilizer effectively inhibited the sintering of CaO and NiO. It delayed the aggregation of CaMoO4, leading to a stable catalytic ability and adsorption capacity of the catalyst.