One-step coating of commercial Ni nanoparticles with a Ni, N-co-doped carbon shell towards efficient electrocatalysts for CO2 reduction

Catalytic Oxidation of Benzene over Atomic Active Site AgNi/BCN Catalysts at Room Temperature

Benzene is the typical volatile organic compound (VOC) of indoor and outdoor air pollution, which harms human health and the environment. Due to the stability of their aromatic structure, the catalytic oxidation of benzene rings in an environment without an external energy input is difficult. In this study, the efficient degradation of benzene at room temperature was achieved by constructing Ag and Ni bimetallic active site catalysts (AgNi/BCN) supported on boron-carbon-nitrogen aerogel. The atomic-scale Ag and Ni are uniformly dispersed on the catalyst surface and form Ag/Ni-C/N bonds with C and N, which were conducive to the catalytic oxidation of benzene at room temperature. Further catalytic reaction mechanisms indicate that benzene reacted with ·OH to produce R·, which reacted with O2 to regenerate ·OH. Under the strong oxidation of ·OH, benzene was oxidized to form alcohols, carboxylic acids, and eventually CO2 and H2O. This study not only significantly reduces the energy consumption of VOC catalytic oxidation, but also improves the safety of VOC treatment, providing new ideas for the low energy consumption and green development of VOC treatment.

Functional Group Regulated Ni/Ti3C2Tx (Tx = F, -OH) Holding Bimolecular Activation Tunnel for Enhanced Ammonia Borane Hydrolysis

Developing economical and efficient catalyst for hydrogen generation from ammonia borane (AB) hydrolysis is still a huge challenge. As an alternative strategy, the functional group regulation of metal nanoparticles (NPs)-based catalysts is believed to be capable of improving the catalytic activity. Herein, a series of Ni/Ti₃C₂T_x-Y (T_x = F, -OH; Y denotes etching time (d)) catalysts are synthesized and show remarkably enhanced catalytic activity on the hydrolysis of AB in contrast to the corresponding without regulating. The optimized Ni/Ti₃C₂T_x-4 with a turnover frequency (TOF) value of 161.0 min^-1 exhibits the highest catalytic activity among the non-noble monometallic-based catalyst. Experimental results and theory calculations demonstrate that the excellent catalytic activity benefits from the bimolecular activation channels formed by Ni NPs and Ti₃C₂T_x-Y. H₂O and AB molecules are activated simultaneously in the bimolecular activation tunnel. Bimolecular activation reduces the activation energy of AB hydrolysis, and hydrogen generation rate is promoted. This article provides a new approach to design effective catalysts and further supports the bimolecular activation model for the hydrolysis of AB.

High-curvature Carbon Supported Ni Single Atom with Charge Polarization for High-efficient CO2 Reduction

High curvature carbon supported isolated NiN4 sites with ideal CO2 reduction reaction performance were obtained through a top-down strategy. The charge polarization induced by the axial asymmetry of carbon substrate...

Ni-N-Doped Carbon-Modified Reduced Graphene Oxide Catalysts for Electrochemical CO2 Reduction Reaction

Electrochemical CO2 reduction reaction (CO2RR) is eliciting considerable attention in relation to the carbon cycle and carbon neutrality. As for the practical application of CO2RR, the electrocatalyst is a crucial factor, but, even so, designing and synthesizing an excellent catalyst remains a significant challenge. In this paper, the coordination compound of Ni ions and dimethylglyoxime (DMG) was employed as a precursor to modify reduced graphene oxide (rGO) for CO2RR. The textural properties and chemical bonds of as-obtained rGO, N–C–rGO, Ni–rGO, Ni–N–C, and Ni–N–C–rGO materials were investigated in detail, and the role of Ni, N–C, and rGO in the CO2RR were researched and confirmed. Among all the catalysts, the Ni–N–C–rGO showed the optimal catalytic activity and selectivity with a high current density of 10 mA cm−2 and FE(CO)% of 85% at −0.87 V vs. RHE. In addition, there was no obvious decrease in activity for 10 h. Therefore, the Ni–N–C–rGO is a promising catalyst for CO2RR to CO.