Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to i...Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.展开更多
Reaction of a tripodal ligand, N,N＇,N＇＇-tris（3-pyridinyl） phosphoric trimide（TPPA） and CuBr_2·2H_2O result in the assembly of a new polymeric copper coordination polymer, which was characterized by single-...Reaction of a tripodal ligand, N,N＇,N＇＇-tris（3-pyridinyl） phosphoric trimide（TPPA） and CuBr_2·2H_2O result in the assembly of a new polymeric copper coordination polymer, which was characterized by single-crystal diffraction, infrared spectroscopy and elemental analysis. The polymer crystallizes in the triclinic system, space group P1 with a = 9.0964（5）, b = 10.2592, c = 10.5822（8） A, V = 933.01（9） A3, Z = 2, C_（30）H_（24）Br_4Cu_3N_（12）O_2P_2, M_r = 985.02, D_c = 1.753 g/cm3, F（000） = 4072 and μ（MoKα） = 0.746 mm^（-1）. The final R and w R are 0.0588 and 0.1329 for 4260 observed reflections with I 〉 2σ（I）. Cu（Ⅰ） is tetrahedrally coordinated and Cu（Ⅱ） center adopts square planar coordination geometry. Because of the flexibility of the TPPA ligands, the pyridyl rings rotate though a certain angle and three pyridyl rings on the same TPPA rotate by about 45° with respect to the central P=O groups. TPPA ligand acts as a tridentate ligand and is coordinated with three metal centers with its pyridyl donors to form a 2D-sheet like structure, and it is further connected by N-H···O and N-H···Br, resulting in a 3D network packing. Oxidation states of the metal center have been determined by bond valence sum calculation.展开更多
基金supported by the Climate Change Response Project (NRF-2019M1A2A2065612)the Brainlink Project (NRF2022H1D3A3A01081140)+3 种基金the NRF-2021R1A4A3027878 and the No. RS-2023-00212273 funded by the Ministry of Science and ICT of Korea via National Research Foundationresearch funds from Hanhwa Solutions Chemicals (1.220029.01)UNIST (1.190013.01)supported by the Institute for Basic Science (IBS-R019-D1)。
文摘Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.
基金supported by the Natural Science Foundation of Shanxi province(2012021005-2)Technology Foundation for Selected Overseas of Shanxi
文摘Reaction of a tripodal ligand, N,N＇,N＇＇-tris（3-pyridinyl） phosphoric trimide（TPPA） and CuBr_2·2H_2O result in the assembly of a new polymeric copper coordination polymer, which was characterized by single-crystal diffraction, infrared spectroscopy and elemental analysis. The polymer crystallizes in the triclinic system, space group P1 with a = 9.0964（5）, b = 10.2592, c = 10.5822（8） A, V = 933.01（9） A3, Z = 2, C_（30）H_（24）Br_4Cu_3N_（12）O_2P_2, M_r = 985.02, D_c = 1.753 g/cm3, F（000） = 4072 and μ（MoKα） = 0.746 mm^（-1）. The final R and w R are 0.0588 and 0.1329 for 4260 observed reflections with I 〉 2σ（I）. Cu（Ⅰ） is tetrahedrally coordinated and Cu（Ⅱ） center adopts square planar coordination geometry. Because of the flexibility of the TPPA ligands, the pyridyl rings rotate though a certain angle and three pyridyl rings on the same TPPA rotate by about 45° with respect to the central P=O groups. TPPA ligand acts as a tridentate ligand and is coordinated with three metal centers with its pyridyl donors to form a 2D-sheet like structure, and it is further connected by N-H···O and N-H···Br, resulting in a 3D network packing. Oxidation states of the metal center have been determined by bond valence sum calculation.
