Ternary Heterostructural Pt/CNx/Ni as a Supercatalyst for Oxygen Reduction

Abstract

We report here a supercatalyst for oxygen reduction of Pt/CN x /Ni in a unique ternary heterostructure, in which the Pt and the underlying Ni nanoparticles are separated by two to three layers of nitrogen-doped carbon (CN x), which mediates the transfer of electrons from the inner Ni to the outer Pt and protects the Ni against corrosion at the same time. The well-engineered low-Pt catalyst shows $780% enhanced specific mass activity or 490% enhanced specific surface activity compared with a commercial Pt/C catalyst toward oxygen reduction. More importantly, the exceptionally strong tune on the Pt by the unique structure makes the catalyst superbly stable, and its mass activity of 0.72 A/mg Pt at 0.90 V (well above the US Department of Energy's 2020 target of 0.44 A/mg Pt at 0.90 V) after 50,000 cyclic voltammetry cycles under acidic conditions is still better than that of the fresh commercial catalyst.

Metal–Organic Frameworks and Metal–Organic Gels for Oxygen Electrocatalysis: Structural and Compositional Considerations

“…The oxygen redox mechanism paths and the rate determining step (RDS) during either four‐electron or two‐electron oxygen electrocatalytic reactions are intrinsic catalyst properties, which are highly dependent on the active site structure and the surrounding environment. [ 32,40 ] The binding free energy (Δ G ) is often used as the descriptor for RDS. For examples, for OER catalysis over oxides, the reaction free energy therefore RDS can vary significantly over different oxides.…”

“…[ 32 ] For ORR catalysis over Pt–transition metal core–shell catalysts, the core composition has strong impact to the RDS. [ 40a ] Different lattice plane could also alter the RDS significantly. [ 40b ] Furthermore, for the same active center bonded over different substrates, the free energy and RDS could change significantly.…”

“…[ 40a ] Different lattice plane could also alter the RDS significantly. [ 40b ] Furthermore, for the same active center bonded over different substrates, the free energy and RDS could change significantly. [ 40c ] Generally, the RDS can be predicted by modeling the catalyst active site structure based on characterization results, followed by performing DFT calculation on the structure to study the free energy change between the intermediate steps during the reaction.…”

Iron oxide encapsulated in nitrogen-rich carbon enabling high-performance lithium-ion capacitor

“…It can significantly enhance the electronic conductivity and improve the rate performance of electrode materials. Moreover, the formation of stable solid electrolyte interface (SEI) films on carbon surface can protect the inner active materials and maintain their high capacities [33][34][35]. On the other hand, a number of battery-type transition metal oxides could exhibit electrochemical pseudocapacitive features through nanostructuring.…”

Bubble-Assisted Three-Dimensional Ensemble of Nanomotors for Improved Catalytic Performance

“…Noble metal nanocrystals have been extensively investigated for achieving high efficiency and yield among organic catalysis (Chen et al., 2019, Dhakshinamoorthy et al., 2018, Jing et al., 2018, Stratakis and Garcia, 2012, Wang et al., 2018a, Wang et al., 2018b, Liu et al., 2019). Owing to the high surface energy, the nanometer-scale catalysts tend to aggregate during the reaction, resulting in catalyst deactivation and difficulties for recycling.…”