Although various inorganic particles have been confirmed as effective trappers to restrict the shuttle effect of lithium polysulfides (LiPSs) in lithium-sulfur batteries (LSB), the further reduction of LiPSs is impeded due to their low conductivity. This process results in sluggish redox kinetics at the interface of cathode/electrolyte and escaped LiPSs to electrolytes during long-term cycling. Herein, by advantageous functional integration of immobilization and conversion capability for LiPSs, a 3D aerogel with the composition of Co@CoO@N-doped carbon@graphene (Co@CoO@N-C/rGO) is designed and prepared. The dual-shells of N-C and polar CoO enable the strong chemical adsorption towards LiPSs through pyridinic – N-Li-bond and Co···S coordination, respectively. And the conductive Co core acts as a “scissor”, which catalyzes the transformation of adsorbed LiPSs into low-order ones, thus accelerating the kinetics of the liquid–solid nucleation and growth of Li S. Moreover, the ma
Abstract
Boosting the alkaline hydrogen evolution and oxidation reaction (HER/HOR) kinetics is vital to practicing the renewable hydrogen cycle in alkaline media. Recently, intensive research has demonstrated that interface engineering is of critical significance for improving the performance of heterostructured electrocatalysts particularly toward the electrochemical reactions involving multiple reaction intermediates like alkaline hydrogen electrocatalysis, and the research advances also bring substantial non-trivial fundamental insights accordingly. Herein, we review the current status of interface engineering with respect to developing efficient heterostructured electrocatalysts for alkaline HER and HOR. Two major subjects how interface engineering promotes the reaction kinetics and what fundamental insights interface engineering has brought into alkaline HER and HOR are discussed. Specifically, heterostructured electrocatalysts with abundant interfaces have shown substantially
Abstract
Tailoring catalysts with balanced adsorption capabilities toward multiple reaction intermediates is highly desirable for complex electrocatalytic reactions, but rather challenging. Here, Ni single atom-decorated carbon nanosheets are developed as multifunctional supports for engineering heterostructured electrocatalysts toward hydrogen evolution in alkaline media. The Ni single atoms (Ni–N ) are actively dedicated to cleaving the H–OH bonds as well as facilitating H spillover to metallic Pt sites. For the case of supported Pt electrocatalysts, a Pt/PtO configuration is generated at the heterointerface via Pt–O–C (Ni) interfacial bonding, with oxidized Pt species located at the interface and metallic Pt formed in the near-interface area. Further, the oxidized Pt species are also active for boosting the water dissociation step. These findings not only open up a new avenue toward the development of multifunctional catalyst supports but also demonstrate the importance
Oxygen evolution reaction (OER) is admitted to an important half reaction in water splitting for sustainable hydrogen production. The sluggish four-electron process is known to be the bottleneck for enhancing the efficiency of OER. In this regard, tremendous efforts have been devoted to developing effective catalysts for OER. In addition to Ir- or Ru-based oxides taken as the benchmark, transition metal carbides have attracted ever-increasing interest due to the high activity and stability as low-cost OER electrocatalysts. In this review, the transition metal carbides for water oxidation electrocatalysis concerning design strategies and synthesis are briefly summarized. Some typical applications for various carbides are also highlighted. Besides, the development trends and outlook are also discussed.
This work describes a coordination enabled galvanic replacement method to decorate atomic Ni clusters on defect-rich Cu surface to provide the first Ni/Cu bimetallic system that significantly enhances the production of C products from electrocatalytic CO reduction. Specifically, with a surface Ni/Cu ratio of 0.82 %, a 7-fold increase in the selectivity for C products was found in comparison with pristine Cu. Density functional theory calculations reveal that the rate determining step for CO formation changes from the formation of COOH on copper to the chemisorption of CO on Ni decorated surfaces. An alteration of binding sites from Ni-Ni bridge for CO and COOH to Ni-Cu bridge for CO is discovered and is proposed to favor the key C–C coupling step. The catalytic mechanism demonstrated in the Cu-Ni system points to the new directions for the development of advanced bimetallic electrocatalysts for producing multi-carbon materials from CO reduction. 2 2 2 2 2 2