Hydrogen, methane and power tri-generation from coal-based fuels in protonic ceramic fuel cells

The traditional utilization of coal fuels is primarily through direct combustion to generate electricity, with low efficiency and significant carbon dioxide emissions conflicting with the goal of carbon neutrality. Here, for the first time, we proposed a novel electrochemical system to achieve the tri-generation of hydrogen, power, and methane from coal-based fuels, with CO2 emission efficiency reduced in tail gas, enabled by protonic ceramic fuel cells (PCFCs) combined with water gasification of coal and CO2 methanation. As demonstrated, the system firstly achieved an enhanced hydrogen production rate of up to 34.8 μmol min−1 g−1 from the syngas produced by coal gasification. Sequentially, the system achieved an excellent peak power density of 868 mW cm−2 at 600 °C in the PCFCs fueled by the syngas, enhanced by a catalytic functional layer (CFL, NiMn@YSZ). In addition, the system is able to produce methane at 6.3 mL min−1 during in-situ CO2 methanation at 500 °C with a current density of 110 mA cm−2. This work introduces a new electrochemical strategy for efficiently utilizing coal to generate electricity and value-added chemicals.