Qinsheng Wang,Yiyi Fan,Chengliang Wu,Yun Jin,Claudia Li,Jaka Sunarso,Xiuxia Meng,Naitao Yang
Research on gas separation membrane has targeted upon maximizing the selectivity and permeance. The development of 2D materials ( e.g. , MXene) gives a novel avenue to surpass the “trade-off” among the membrane selectivity and permeability. However, randomly stacked nanosheets and the regulation of interlayer spacing for MXene nanosheets hinder the development of MXene membrane. To this end, we designed a Pd-intercalated lamellar MXene membrane to modify the surface chemical properties (H-spillover effect) of MXene (Ti 3 C 2 T x ) and to expand the interlayer spacing (from 2.29 to 3.26 Å) due to the strong interaction between Pd 2+ and MXene nanosheets with negative charge. Here, we performed a single-step etching approach to prepare 2D Pd-MXene membrane and demonstrated its excellent H 2 permeability of 2.66 × 10 −7 mol m −2 s −1 ·Pa −1 and H 2 /CO 2 selectivity of 242 at 25 °C, which greatly exceeds the current benchmark membranes. We also developed single gas transport mathematical mechanism models to interpret and support the experimental results. The combined experimental and modeling results show that interlayer spacing and H-spillover effect of Pd-MXene membrane benefit H 2 /CO 2 separation.
Mao Qiqi,Mu Xu,Wang Wenxin,Deng Kai,Yu Hongjie,Wang Ziqiang,Xu You,Wang Liang,Wang Hongjing
Organic electrocatalytic conversion is an essential pathway for the green conversion of low-cost organic compounds to high-value chemicals, which urgently demands the development of efficient electrocatalysts. Here, we report a Cu single-atom dispersed Rh metallene arrays on Cu foam for cathodic nitrobenzene electroreduction reaction and anodic methanol oxidation reaction. In the coupled electrocatalytic system, the Cu single-atom -Rh metallene arrays on Cu foam requires only the low voltages of 1.18 V to reach current densities of 100 mA cm −2 for generating aniline and formate, with up to ~100% of nitrobenzene conversion/ aniline selectivity and over ~90% of formate Faraday efficiency, achieving synthesis of high-value chemicals. Density functional theory calculations reveal the electron effect between Cu single-atom and Rh host and catalytic reaction mechanism. The synergistic catalytic effect and H*-spillover effect can improve catalytic reaction process and reduce energy barrier for reaction process, thus enhancing electrocatalytic reaction activity and target product selectivity.
危险品化学品经营许可证（带存储）