Study on the catalytic activity of char-based Fe–Co–K catalyst for volatiles reforming during biomass pyrolysis

This work studied the catalytic activity of char-loaded Fe, Co, and K catalyst for the reforming of volatiles of biomass pyrolysis in a two-stage fixed-bed reactor under 0.1 MPa N2 and 800 °C, reforming temperature 600 °C. The results showed that the addition of Co do not exhibit the desired catalytic activity and the yield of H2 decreased from 163.08 mL/g (9Fe/Char) to 152.30 mL/g (9Fe0.5Co/Char). While, with the addition of K, the catalytic activity of Fe–Co-based catalyst was improved, and the H2 yield increased from 95.16 mL/g(raw pine needle)to 179.10 mL/g (9Fe0.5Co0.4K/Char). In addition, K do not enhance the catalytic activity of Co. The characterization results showed that the addition of K favorable the formation of the active phase Fe3O4, that helped to increase the H2 yield. Which due to K combined with oxygen-containing functional groups and captured O to form lattice oxygen (K(O∗)), transferred to the oxygen vacancy of Fe (Fe( )) through intermetallic interaction, and finally formed Fe3O4. Co is easily oxidized to form Co3O4, and it is not possess catalytic activity. The addition of K promoted the oxidation of Co, which leads to the loss of catalytic activity. The study developed a low-cost Fe–Co–K/Char catalyst exhibits a promising application in the catalytic reforming of biomass pyrolysis to hydrogen-rich gas.