Development of Ru-Decorated Carbon Nanotubes-Supported Catalyst for a Microchannel Methanation Reactor

In this study, MWNT and alumina nanopowder were used as a ruthenium catalyst support for the conversion of carbon monoxide to methane. Metal foam structures were employed to support such catalytic systems, offering interesting possibilities for commercial applications due to low-pressure drop; excellent flow characteristic and heat transfer properties. Prior to the ruthenium impregnation, the MWNT surface was initially modified by means of metal cation activation and surface adsorption of anionic surfactant. The decoration processes using both surface modifications promoted the deposition of ruthenium with a mean 2 nm diameter. The use of nickel as a nucleating center enhanced the Ru nanoparticle density on the CNT surface compared to the Ru/CNT catalyst prepared by excess solution impregnation. As a reducing agent, ethylene glycol completely converted Ru2＋ to Ru0as confirmed by an EDS/TEM analysis. Among the prepared catalysts, Ru/AI203-CNTs prepared by Ni2＋ activation showed the best performance for the hydrogenation reaction. This is interpreted in terms of the higher ruthenium nanoparticle exposure on the nanostructured catalyst, as a result of the better MWNT dispersion in the MWNT/Al2O3 mixture.

Efficient electrochemical reduction of CO to C_(2) products on the transition metal and boron co-doped black phosphorene

The synthesis of high-value multi-carbon products through the electrochemical reduction of carbon monoxide(COER) is one of the promising avenues for carbon utilization and energy storage,in which searching for efficient electrocatalysts that exhibit moderate CO intermediate binding strength and low kinetic barrier for C-C coupling is a key issue.Herein,by means of comprehensive density functional theory(DFT) computations,we theoretically designed three synergistic coupling catalysts by co-doping transition metal(TM=Fe,Co and Ni) and boron(B) into the two-dimensional black phosphorene(BP),namely TMB@BP for COER to C_(2) products.DFT computations and ab initio molecular dynamics simulations reveal the good stability and high feasibility of these proposed TM-B@BP catalysts for practical applications and future experimental synthesis.More interestingly,high-value ethylene(C_(2)H_(4)),ethane(C_(2)H_(6)) and ethanol(C_(2)H_(5)OH) products can be obtained on these three designed electrocatalysts with ultra-small limiting potentials(-0.20~-0.41 V) and low kinetic energy barriers of C-C coupling(0.52~0.91 eV).Meanwhile,the competitive one-carbon(C_(1)) products and hydrogen evolution reaction can also be effectively suppressed.The promising activity and selectivity of these three designed electrocatalysts render them ideal candidates for CO electroreduction,thus providing a cost-effective opportunity to achieve a sustainable production of high value C_(2) chemicals and fuels.

Electrolyzer and Catalysts Design from Carbon Dioxide to Carbon Monoxide Electrochemical Reduction

Electrochemical CO_(2)reduction reaction(CO_(2)RR)has attracted considerable attention in the recent decade for its critical role in the storage of renewable energy and fulfilling of the carbon cycle,and catalysts with varying morphology and modification strategies have been studied to improve the CO_(2)RR activity and selectivity.However,most of the achievements are focused on preliminary reduction products such as CO and HCOOH.Development and research on electrochemical CO reduction reaction(CORR)are considered to be more promising to achieve multicarbon products and a better platform to understand the mechanism of C-C formation.In this review,we introduce the current achievements of CO_(2)RR and emphasize the potential of CORR.We provide a summary of how electrolysis environment,electrode substrates,and cell design affect the performance of CORR catalysts in order to offer a guideline of standard operating conditions for CORR research.The composition-structure-activity relationships for CORR catalysts studied in H-cells and gas-phase flow cells are separately analyzed to give a comprehensive understanding of the development of catalyst design.Finally,the reaction mechanism,latest progress,major challenges and potential opportunities of CORR are also analyzed to provide a critical overview for further performance improvement of CORR.