Search

A novel electrochemical route for efficient cycloaddition of CO 2 and styrene oxide (SO) forming the value-added product of styrene carbonate (SC) was proposed in this manuscript using non-metallic nanocarbon material as the catalyst electrode. The synthesized hollow nanospheres (HNSs) nanocarbon materials exhibited unique advantages of porous structure with thin carbon layer, which effectively facilitated the mass and charge transfer process and promoted the electrochemical reaction kinetics. In addition, correlation between the detailed structure analysis and the catalytic activity evaluation results show that the cooperation of nitrogen and oxygen functionalities on nanocarbon played a vital role in enhancing the catalytic activity of the carbon materials. The optimized HNSs catalyst exhibited high SO conversion of 66.9% and SC selectivity of 99.8% under the chronoamperometry at −0.5 mA for 6 hs, showing great potential in practical applications. The structure-function relations reported here may shed light on the rational design of the nanocarbon catalyst electrode and related reaction system for electrochemical synthesis of SC. [Display omitted] • Electrochemical cycloaddition of CO 2 to value-added SC using non-metallic nanocarbon. • N, O co-doped hollow nanospheres nanocarbon with high mass and electron transport capacity. • N, O co-doped nanocarbon showing SO conversion of 66.9% and SC selectivity of 99.8% at −0.5 mA for 6 hs. [ABSTRACT FROM AUTHOR]

A novel electrochemically assisted cycloaddition process is proposed, in which highly efficient coupling of CO2 with styrene oxide (SO) can be achieved to form styrene carbonate (SC) as a high‐value‐added product. A series of Cu catalysts with different morphologies and chemical states were fabricated on carbon paper (CP) by using in‐situ electrodeposition, and the sample with nano‐dendrimer structure was found to exhibit a relatively high activity of 74.8 % SC yield with 92.7 % SO conversion under gentle reaction conditions, thus showing its potential for practical applications. The relatively high electrochemically active surface area and charge transfer ability of dendrimer‐like Cu benefited the electrochemical reaction. In particular, the Cu2+ species that were formed in situ during the reaction played a vital role in enhancing the activity and selectivity of the proposed Cu/CP hybrid catalyst. Cu2+ atoms served as active sites that can not only electrochemically activate CO2 but also facilitate the ring opening of SO. Mechanistic analysis suggested that the reaction followed electrochemical and liquid‐phase heterogeneous paths, which provide a new green and sustainable route for efficient utilization of CO2 resources for fine chemical electrosynthesis. [ABSTRACT FROM AUTHOR]

• Cu single-atom on N-doped carbon materials by supercritical CO 2 deposition. • N-doped carbon is a mesoporous material with a high surface area of 1301 m2/g. • Atomically dispersed metal atoms were prepared without further post-treatment. • AC-HAADF-STEM confirms that Cu atoms are equally dispersed over the NC support. • Cu-NC shows excellent performance in oxidation of benzyl alcohol to benzaldehyde. ga1 Cu single atoms dispersed on N-doped carbon materials (Cu-NC) were obtained after supercritical CO 2 deposition and decompression, without further post-treatment. AC-HAADF-STEM, STEM, XRD, ICP-OES, and XPS results confirmed that the Cu atoms were equably dispersed over the N-doped carbon (NC) support with the loading of 0.80 wt%. The catalytic performance of Cu-NC in solvent-free oxidation of phenylcarbinol to benzaldehyde was investigated, and the conversion of 73.9% and selectivity of 85.7% were obtained at 50 °C for 1 h. A high-pressure view cell was used to observe the dissolution and diffusion for Cu(acac) 2 in scCO 2. The stability of Cu-NC structures and the formation path of active oxygen species (O*) on different configurations were predicted by density functional theory (DFT) calculations, and CuN 3 C 1 was found to be more conducive to the activation of tert-butyl hydroperoxide (TBHP). [ABSTRACT FROM AUTHOR]