A closely packed Pt_1.5Ni_1−x/Ni–N–C hybrid for relay catalysis towards oxygen reduction

Abstract

A closely packed hybrid electrocatalyst Pt1.5Ni1−x/Ni–N–C was engineered by a gas-promoted dealloying process, ensuring the relay catalysis of the reaction intermediates at Pt alloy and Ni single sites, thus achieving high performance in PEMFCs.

Defect engineering of two-dimensional materials for advanced energy conversion and storage

“…One is the direct reduction of O 2 to water (under acidic conditions) or OH À (under alkaline conditions) with an efficient 4e À transfer process, which is more favorable in practical applications like fuel cells. [294][295][296][297] The other is a twostep 2e À transfer route involving the generation of H 2 O 2 (under acidic conditions) or HO 2 À (under alkaline conditions) as the intermediates, which is often used for industrial H 2 O 2 production. [298][299][300][301] Specifically, for the direct 4e À pathway, there are two possible mechanisms with different intermediates involved (associative: O*, OOH*, and OH*; dissociative: O* and OH*) depending on the original O 2 dissociation energy barrier.…”

Single-atom catalysts for electrochemical applications

“…90 More strategies tend to combine Pt-based alloys and single-atom catalysts synergistically to achieve an efficient ORR under acid conditions. [91][92][93] As for ORR, the majority of the electrochemical ORR proceeds through a direct four-electron transfer pathway by reducing O 2 to OH-or H 2 O as final products in a basic or acidic solution. However, the rest of the electrochemical ORR proceeds with twoelectron transfer by reducing O 2 to H 2 O 2 .…”

Enhancement Mechanism of Pt/Pd-Based Catalysts for Oxygen Reduction Reaction

“…This effect may not improve the intrinsic catalytic activity of the catalyst, but it can have a positive impact on catalysis by improving the conductivity of the catalyst, optimizing the reaction process and the interface hydrophilicity, enhancing the mass transport, etc. [ 33 , 43 , 44 , 45 , 46 , 47 ]. On the one hand, the support material may produce strong electron coupling with the catalyst, improve the electronic structure of the catalyst and enhance the catalytic activity of the catalyst.…”

“…On the one hand, the support material may produce strong electron coupling with the catalyst, improve the electronic structure of the catalyst and enhance the catalytic activity of the catalyst. On the other hand, the support material may have a certain optimization effect on the catalytic process and have a positive impact on the reaction kinetics [ 43 , 46 ].…”