CaMoO4-enhanced Ni-CaO bifunctional catalyst for biomass pyrolysis to produce hydrogen-rich gas

The development and utilization of bifunctional catalysts facilitated hydrogen-rich gas production from biomass pyrolysis to achieve high-value biomass conversion. The effects of different secondary metals (Fe, Mo, Ce) doping and Mo addition ratios on the performance of biomass catalytic pyrolysis for hydrogen production were investigated. The results showed that the Mo0.5Ni1Ca7 catalyst had the best catalytic activity, where the H2 percentage was 69.59 vol%, and the yield reached 617.57 mLgbiomass−1. The CO2 concentration of the Mo0.5Ni1Ca7 catalyst was reduced by 10.6% compared to the Ni1Ca7 catalyst, which enhanced the adsorption performance of the catalyst. The intense interaction between Mo and Ca formed CaMoO4, which inhibited the formation of CaCO3 and promoted the dispersion of the active phase. The Mo0.5Ni1Ca7 catalyst had the largest NiO/Ni (OH)2 ratio and Mo6+/Mo5+ ratio, further enhancing the catalyst's stability and catalytic activity. Considering the effect of pyrolysis temperature on H2 concentration and yield, it was found that 600 °C was a relatively suitable catalytic pyrolysis temperature. This paper explored using Mo-modified catalysts in biomass catalytic pyrolysis for the first time, providing new ideas for developing bifunctional adsorption catalysts. Eventually, it provided a new way for biomass pyrolysis for hydrogen production technology.