Defective nanomaterials for electrocatalysis oxygen reduction reaction

Abstract

The difficulties in O2 molecule adsorption/activation, the cleavage of the O–O bond, and the desorption of the reaction intermediates at the surface of the electrodes make the cathodic oxygen reduction reaction (ORR) for fuel cells show extremely sluggish kinetics. Thus, it is important to the exploitation of highly active and stable electrocatalysts for the ORR to promote the performance and commercialization of fuel cells. Many studies have found that the defects affect the electron and the geometrical structure of the catalyst. The catalytic performance is enhanced by constructing defects to optimize the adsorption energy of substrates or intermediates. Unfortunately, still many issues are poorly recognized, such as the effect of defects (types, contents, and locations) in catalytic performance is unclear, and the catalytic mechanism of defective nanomaterials is lacking. In this review, the defective electrocatalysts divided into noble and non-noble metals for the ORR are highlighted and summarized. With the assistance of experimental results and theoretical calculations, the structure–activity relationships between defect engineering and catalytic performance have been clarified. Finally, after a deeper understanding of defect engineering, a rational design for efficient and robust ORR catalysts for PEMFCs is further guided.

Highly Efficient Oxygen Electrode Obtained by Sequential Deposition of Transition Metal-Platinum Alloys on Graphene Nanoplatelets

“…The presence of defects (e.g., point, line, plane, or volume defects) in the crystal structure results in the variation of material properties, including electrical and chemical activity [41,42]. The local electronic state of the catalyst can be redistributed, affecting the adsorption energy of the intermediate species.…”

Editorial: Defect chemistry in electrocatalysis

“…Defect engineering on carbon-based and metal-based single-atom electrocatalysts was highlighted by (Li et al, 2022b) along with the discussions of their characterization. Defective Noble metal and non-noble metal catalysts for electrocatalytic oxygen reduction reaction were discussed and summarized by (Mao et al, 2022) Based on experimental results and theoretical calculations, they clarified the structure-activity relationships between defect engineering and catalytic performance. Oxygen vacancies engineering in electrocatalysts for nitrogen reduction reaction was summarized by (Zhu et al, 2022) They focused on the methods to generate oxygen vacancies and their effects on electrocatalytic nitrogen reduction reaction.…”