Enhancing inter-particle microwave discharge for efficient coke-CO2 gasification

•Inter-particle microwave discharge can effectively promote coke-CO2 gasification.•Carbon conversion increases 18.0–30.6% by the enhanced microwave discharge.•Catalysts can be replaced by enhanced inter-particle microwave discharge.•Increasing the ratio of excited states CO2 can enhance the coke-CO2 gasification.•The excited states CO2 reduces the energy barrier of dissociative adsorption of CO2.