2020同步年報

058 ACTIVITY REPORT 2020 Ru, accompanied by electron delocalization and electron transfer from Ru 3 d orbitals to N ads 2p orbitals, thus implementing activation. This activated N 2 can be reduced continuously via hydrogenation at applied potentials. In summary, the authors developed a chemically activated MXene with rich Mo-deficit defect sites with spontaneous Ru atomic doping for high-performance NRR catalysis under ambient conditions. The specific mechanism of this excellent ac- tivity was unveiled through operando XAS measurements. This work opens an avenue to rational design of MXene-based electrocatalysts and highlights the atomic-doping engineering strategy to manipulate effectively the catalytic performance of electrocatalysts. (Reported by Yan-Gu Lin) This report features the work of Yongwen Tan and his collaborators published in Adv. Energy Mater. 10 , 2001364 (2020). TLS 01C1 SWLS – EXAFS • XANES, EXAFS • Materials Science, Chemistry, Condensed-matter Physics, Environmental and Earth Science Reference 1. W. Peng, M. Luo, X. Xu, K. Jiang, M. Peng, D. Chen, T.-S. Chan, Y. Tan, Adv. Energy Mater. 10 , 2001364 (2020). Heterogeneous Metal-Metal and Metal-Oxide Interfaces of Nanocatalysts Enable CO 2 Reduction with High Performance Sub-nanometer heterogeneous interface induces lattice strain and electronegativity gradient in neighboring local domains and thus enabling the high selectivity and activity of CO 2 reduction in nanocatalysts. M itigation of the global energy crisis and adverse climatic impacts (increasing emission of carbon dioxide, CO 2 ) relies on the implementation of a sustainable energy economy. In this context, catalytic transformations of CO 2 to fuel/chemical feedstocks is the greatest accom- plishment to diminish the carbon emission by industry. The most effective techniques for CO 2 reduction (CO 2 R) include thermal and electrochemical reactions that can respectively be adopted to recycle industrial exhaust gas and to the con- version of green energies. Regardless of the aformentioned techniques, metal-metal and metal-oxide interfaces in a sin- gle nanoparticle have been proved to be the most efficient geometric design among heterogeneous catalysts for CO 2 R. To this end, in thermal CO 2 R, Tsan-Yao Chen from National Tsing Hua University, with the cooperation of Xin Tu (Uni- versity of Liverpool, UK), Dai Sheng (East China University of Science and Technology, China), Kuan-Wen Wang (National Central University, Taiwan), Jr-Hau He (City University of Hong Kong, Hong Kong) and Chia-Hsin Wang (NSRRC), has recently developed a hierarchically structured bimetallic nanocatalyst (NC) comprising a metallic Pd-nanocluster adjacent to local tetrahedrally symmetric Ni-oxide and a thin layer of tetramethyl orthosilicate decoration (denoted as NiO T Pd-T) that was synthesized by sequential control of the metal-ion adsorption followed by wet chemical reduc- tion on the carbon nanotube support at room temperature ( Fig. 1(a) ) 1 . By cross-referencing the results of the X-ray photoemission spectrum in situ ( Figs. 1(b) and 1(c) ), other X-ray spectroscopic and electron microscopic techniques, they confirmed the local synergetic collaboration induced at the interface between metallic Pd and Ni oxide, which enables the intermediate steps in the methanation of CO 2 . Compared to a pure Pd NC, the NiO T Pd-T NC exhibited a superior yield of CH 4 production, 1905.1 μmol/g catalyst at 300 o C. Moreover, the NiO T Pd-T NC surpassed existing catalysts with the same loading and composition and of any geo- metric configuration. In this study, NSRRC beamlines TLS 01C1 and TLS 24A1 were used. Furthermore, in electrochemical CO 2 R, Dr. Hao-Ming Chen (National Taiwan University) and his co-workers developed silver(Ag)-modified copper (Cu) nanowires as effective electrocatalysts towards electrochemical CO 2 reduction (CO 2 RR). 2 Cu 68 Ag 32 nanowires as prepared demonstrated the best performance towards methane with Faradaic