Promotion of microwave discharge over carbon catalysts for CO2 reforming of CH4 to syngas

The discharge (microplasma) of carbon materials in microwave fields can activate reaction molecules and pro-mote the reaction process. This paper studied the microwave discharge characteristics under different carbon materials, particle sizes, particle structures, and microwave electric/magnetic fields. Combining microwave short-term pulse reaction experiments and spectroscopic experiments, the effect of discharge on reforming re-actions was analyzed. The results show that: different carbon materials had different discharge intensities, but they all produced star-shaped sparks. Particles with cis-fiber structure and tips placed in opposition to each other were easier to discharge in microwave electric fields. In the same type of activated carbon, the 0.6 mm coconut shell activated carbon has many discharge sites and high discharge frequency, so the reaction effect was the best. The reactant conversions reached more than 80 %, the syngas yield was 92 %, and the H2/CO was about 1.1. The discharge could promote the activation and decomposition of reaction gas and improve the conversion of reactants.