Designing highly active and stable electrocatalysts of oxygen evolution reaction(OER)is one of the crucial challenges.In this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium(Rh@NiFe-MIL-5...Designing highly active and stable electrocatalysts of oxygen evolution reaction(OER)is one of the crucial challenges.In this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium(Rh@NiFe-MIL-53),is successfully prepared via the hydrothermal method.In-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active species.More importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe(OH)_(2)after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@NiFeOOH.Furthermore,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center(εd),accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining steps.Consequently,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity(240 mV)with a small Tafel slope of 48.2 mV dec^(-1)and long-term durability(over1270 h at 10 m A cm^(-2)and 110 h at 200 mA cm^(-2)).This work presents a new perspective on designing highly efficient OER electrocatalysts.展开更多
The chemisorption and direct decomposition of NO on Rh（100） and Rh（111） surfaces were studied by the density functional theory（DFT） with Dmol3 program.The calculation results show that for the Rh（100）surface,t...The chemisorption and direct decomposition of NO on Rh（100） and Rh（111） surfaces were studied by the density functional theory（DFT） with Dmol3 program.The calculation results show that for the Rh（100）surface,the bridge sites are found to be the preferred adsorption site,but for the Rh（111） surface,the three fold hollow（hcp） sites are found to be the most stable one;the transition states were confirmed for the direct decomposition of NO on Rh（100） and Rh（111） surfaces by successful transition state search,and the activation energy are 161.91 kJ/mol for Rh（100） and 183.72 kJ/mol for Rh（111）,respectively.展开更多
基金Natural Science Foundation of China(Grant No.NSFC-22072062,22202098)。
文摘Designing highly active and stable electrocatalysts of oxygen evolution reaction(OER)is one of the crucial challenges.In this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium(Rh@NiFe-MIL-53),is successfully prepared via the hydrothermal method.In-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active species.More importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe(OH)_(2)after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@NiFeOOH.Furthermore,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center(εd),accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining steps.Consequently,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity(240 mV)with a small Tafel slope of 48.2 mV dec^(-1)and long-term durability(over1270 h at 10 m A cm^(-2)and 110 h at 200 mA cm^(-2)).This work presents a new perspective on designing highly efficient OER electrocatalysts.
文摘The chemisorption and direct decomposition of NO on Rh（100） and Rh（111） surfaces were studied by the density functional theory（DFT） with Dmol3 program.The calculation results show that for the Rh（100）surface,the bridge sites are found to be the preferred adsorption site,but for the Rh（111） surface,the three fold hollow（hcp） sites are found to be the most stable one;the transition states were confirmed for the direct decomposition of NO on Rh（100） and Rh（111） surfaces by successful transition state search,and the activation energy are 161.91 kJ/mol for Rh（100） and 183.72 kJ/mol for Rh（111）,respectively.
