Substantial energy penalty of valuable sulfate recovery restricts the efficiency of wet desulfurization and increases the risk of Hg0 reemission. Although the enhanced sulfite oxidation rate with cobalt-based materials can increase the energy efficiency, inactivation and poisoning of catalyst due to the competition of reactant must be addressed. Here we obtained a superwetting two-dimensional cobalt-nitrogen-doped carbon (2D Co-N-C) nanosheet featuring confined catalysis/adsorption sites for the energy-efficient sulfite oxidation and Hg2+ adsorption. The designed structure exhibits enhanced surface polarity, availability and short reactant diffusion path, thus enabling the significant catalytic TOF value of 0.085 s-1 and simultaneous mercury removal ability of 143.26 mg·g-1. The catalyst nanosheets present regenerating stabilities to improve cost-efficiency. By deployment of the Co-N-C catalysts, a marked reduction of heat penalty up to 69% can be achieved, which makes this catalytic pathway for sulfur resource recovery economically feasible in real industry scenario.
Keywords: N-doped carbon catalyst; confined active sites; desulfurization; mercury uptake; sulfite resource recovery.