Plasma-catalytic biogas reforming for hydrogen production over K-promoted Ni/Al2O3 catalysts: Effect of K-loading

Biogas reforming for hydrogen production was achieved in a tabular dielectric barrier discharge (DBD) system using K-promoted Ni/Al2O3 catalysts with varying potassium loadings. The Ni-K/Al2O3 catalyst with 2 wt% K loading showed the best reforming performance with a CH4 conversion of 32% and a CO2 conversion of 23%, resulting in the highest energy efficiency of 0.67 mmol kJ(-1) among the studied catalysts. In comparison to the unpromoted Ni/Al2O3 catalyst, the presence of 2 wt% potassium loading enhanced H-2 production while suppressing CO formation, increasing the relative amount of H-2 in the syngas. Furthermore, the Ni-K/Al2O3 catalyst (2 wt% K) exhibited the most pronounced plasma-catalytic synergy. The results of thermal gravimetry analysis (TGA) revealed that increasing potassium loading in the catalysts increased carbon production by generating more inactive and less active carbonaceous species (C-gamma and C-beta) on the catalyst surfaces. This study demonstrates that by tuning the potassium loading of Ni/Al2O3 based catalysts, the performance of plasma-catalytic biogas reforming at low temperatures can be enhanced.

Automated summary

Biogas reforming for hydrogen production was achieved using K-promoted Ni/Al2O3 catalysts in a tabular dielectric barrier discharge system. The catalyst with 2 wt% K loading exhibited the best reforming performance and highest energy efficiency, enhancing H2 production while suppressing CO formation.