Recovered Carbon from Coal Gasification Fine Slag as Electrocatalyst for Oxygen Reduction Reaction and Zinc–Air Battery

Abstract

The coal gasification industry produces a large amount of coarse and fine slag. Such slag, which is composed mainly of carbon residues and inorganic species, e.g., silicon, calcium, magnesium, and aluminum, becomes a tough problem because of the environmental concerns and high reusage cost. Benefiting from the carbon‐rich feature, such cheap byproducts of the coal gasification industry can be used as precursors to prepare porous carbons for energy conversion and storage. Herein, new porous carbons are prepared by treating carbon‐rich fine slag by direct acid etching and ammonia activation. The oxygen reduction reaction performance of as‐developed porous carbons as electrocatalysts is evaluated in alkaline media. Then, such porous carbons are further utilized as air cathodes for a zinc–air battery and reach a power density of 88 mW cm−2 at the current density of 154.9 mA cm−2. All these results indicate that fine slag, a byproduct of the coal gasification industry, has a great potential to be reused as a high‐value electrocatalyst and electrode for energy conversion and storage.

Investigation of the Heteroatom Doping Effect on Gasification Fine Slag Residue Carbon Oxygen Reduction Reaction Catalysts

“…The world's energy consumption is still dominated by fossil fuels, and coal consumption in China accounts for about 60% of its total energy consumption. [1] With a large amount of coal as an energy supply, a cleaner and more efficient way of coal utilization-coal gasification technology-has been developed and applied on a large scale. [2,3] However, a large number of minerals and incompletely gasified carbon particles in the coal are discharged out of the furnace with the combustible gas to form gasification fine slag (GFS).…”

Upcycling endogenous Fe from coal gasification slag waste into a cocatalyst for the photocatalytic H2 evolution reaction

“…[9][10][11][12][13] At present, the most feasible approach for utilizing CGS waste is the manufacturing of low-value-added construction and paving materials. [14][15][16][17] Alternatively, many studies have also explored the recovery of unburned carbon [18][19][20] as well as a series of Si and Al-based porous materials [21][22][23][24][25][26] from CGS via remediation methods, like physical flotation and chemical precipitation/ extraction, which require post-treatment of CGS, the use of reagent-grade chemicals, and extensive electricity input, which are usually accompanied by high energy costs and large CO 2 emission. In the meantime, the production of high-quality carbon and silica products from CGS requires an additional acid leaching step to remove the naturally endogenous metal impurities, 27,28 which not only further increases the cost of mass production but also enhances the possibility of metal wastes entering natural water systems, resulting in serious diseases in humans.…”

Mesoporous Spherical Silica Filler Prepared from Coal Gasification Fine Slag for Styrene Butadiene Rubber Reinforcement and Promoting Vulcanization

“…The utilization of CFS in this field achieved the goal of treating waste with waste. Furthermore, high-performance absorbents for CO 2 capture [ 13 ], microwave absorbers [ 14 ], conductive powders [ 15 ], and air cathodes for zinc–air batteries [ 16 ] were prepared from CFS due to the advantages of their hierarchical porous and thermal stability. The utilization of CFS in the abovementioned fields has achieved encouraging results.…”