Fe/N/S Co-doped Porous Carbon from the Co-processing Residue of Coal and Heavy Oil for an Efficient Oxygen Reduction Reaction

Abstract

The development of novel non-noble electrocatalysts to replace Pt-based materials has always been the focus of electrocatalysis research. The co-processing residue of coal and heavy oil (CR) is a carbonaceous waste with high quantities of heteroatomic compounds from coal liquefaction industries. With the aid of alkali activation and melamine doping operations at a high temperature, the CR was transformed into a material with a large specific surface area, rich hierarchical pores, and Fe, N, and S doping for application in the oxygen reduction reaction (ORR) as an electrocatalyst. The structural features and reaction performances of synthesized electrocatalysts with different components in the CR as precursors were compared. The ORR half-wave potential of the electrocatalyst with the direct utilization of the CR (0.82 V) was close to the commercial 20% Pt/C (0.85 V) under alkaline conditions, which surpassed that of the electrocatalysts derived from the toluene-soluble (0.78 V) or toluene-insoluble (0.79 V) components in the CR. The asphaltenes in the toluene-soluble component of CR and the mineral templates and the Fe-containing active species in the toluene-insoluble component of CR showed a synergistic effect on the improvement of ORR performances, which may shed light on the high-valued utilization of CR materials.

l-Alanine-Assisted Synthesis of a Hierarchically Porous Co@N–C/N-Ketjenblack Carbon Catalyst for Oxygen Reduction in Zn–Air Batteries

“…Zinc–air batteries (ZABs) are presently attracting a lot of interest as a power due to their high theoretical specific energy capacity (1086 W h kg –1 ), inherent safeness, non-toxicity, and low cost. , However, the practical energy capacity of ZABs is presently much lower than the theoretical value and one of the main reasons for it is the sluggish kinetics of four-electron-transfer oxygen reduction reaction (ORR) that occurs on the air cathode during battery discharge. , Currently, Pt-based catalysts are typically used in ZABs to drive the ORR. However, the high cost, scarcity, and poor stability of Pt-based catalysts represent obstacles to the widespread application of ZABs. − Hence, the discovery of highly efficient non-precious metal-based electrocatalysts for ORR is an imperative. − …”