Solvent-free synthesis of N-doped nanoporous carbon materials as durable high-performance pH-universal ORR catalysts.

Metal-free carbons as durable high-performance oxygen reduction electrocatalysts, deemed to be promising alternatives to the platinum-group metals (PGMs), are vital to large-scale commercialization of fuel cells. Herein, a solvent-free synthetic strategy has been proposed to prepare N-doped nanoporous metal-free carbonaceous materials originating from various types of plant residues (papaya skin - fruit, bamboo shoot - forestry, wheat straw - farming and cabbage stem - vegetable). The optimal metal-free carbon, possessing maximized reaction surface area and optimized distributions of nanopore structures and nitrogen species, can function as the durable high-performance pH-universal ORR electrocatalyst, reaching or surpassing the benchmark 20% Pt/C catalyst within the wide scope of pH.

Ultrasound-assisted transformation from waste biomass to efficient carbon-based metal-free pH-universal oxygen reduction reaction electrocatalysts.

Efficient carbon-based nitrogen-doped electrocatalysts derived from waste biomass are regarded as a promising alternative to noble metal catalysts for oxygen reduction reaction (ORR), which is crucial to fuel cell performance. Here, coconut palm leaves are employed as the carbon source and a series of nitrogen-doped porous carbons were prepared by virtue of a facile and mild ultrasound-assisted method. The obtained carbon material (ANDC-900-10) conveys excellent pH-universal catalytic activity with onset potentials (E) of 1.

Harnessing inherently hierarchical microstructures of plant biomass to construct three-dimensional nanoporous nitrogen-doped carbons as efficient and durable oxygen reduction electrocatalysts.

Exploiting the natural structures of plants to prepare high-performance carbon-based electrocatalysts is highly desirable. Herein, the inherently hierarchical microstructures of () are employed to construct three-dimensional nanoporous nitrogen-doped carbons that act as efficient and durable electrocatalysts towards the oxygen reduction reaction (ORR). During the preparation process, agar is used in order to reduce the dissipation of nitrogen and to protect the fine structures of .

Template-free preparation of anthracite-based nitrogen-doped porous carbons for high-performance supercapacitors and efficient electrocatalysts for the oxygen reduction reaction.

The conversion of coal into high-performance electrochemical energy materials, exemplified by electrodes and electrocatalysts for supercapacitors and fuel cells, is currently crucial to the advancement of high value-added, clean and non-fuel utilization of coal resources. In this work, anthracite-based nitrogen-doped porous carbon (ANPC) materials with well-defined pore architectures and adjustable nitrogen concentrations were prepared without any template: ANPC-1 by a one-step activation/doping process and ANPC-2 by a two-step process. The specific capacitance value of the ANPC-1 materials could attain a maximum of 346.

Solvent-Free Mechanochemical Preparation of Hierarchically Porous Carbon for Supercapacitor and Oxygen Reduction Reaction.

Hierarchically porous carbon (HPC) derived from fallen flowers was prepared by a green method of combining solvent-free ball milling with the safe activating agent potassium bicarbonate. By regulating the mass ratio of KHCO to biochar, the as-prepared HPC materials possess high specific surface areas of up to 2147.9 m  g and abundant hierarchical pores comprised of micro-, meso-, and macropores.