Bimetallic catalysts can improve CO2 reduction efficiency via the combined properties of two metals.CuPd shows enhanced CO2 reduction activity compared to copper alone.Using differential electrochemical mass spectrome...Bimetallic catalysts can improve CO2 reduction efficiency via the combined properties of two metals.CuPd shows enhanced CO2 reduction activity compared to copper alone.Using differential electrochemical mass spectrometry(DEMS)and electrochemical infrared(IR)spectroscopy,volatile products and adsorbed intermediates were measured during CO2 and CO reduction on Cu and CuPd.The IR band corresponding to adsorbed CO appears 300 mV more positive on CuPd than that on Cu,indicating acceleration of CO2 reduction to CO.Electrochemical IR spectroscopy measurements in CO-saturated solutions reveal similar potentials for CO adsorption and CO3^2-desorption on CuPd and Cu,indicating that CO adsorption is controlled by desorption of CO3^2-.DEMS measurements carried out during CO reduction at both electrodes showed that the onset potential for reduction of CO to CH4 and CH3OH on CuPd is about 200 mV more positive than that on Cu.We attribute these improvements to interaction of Cu and Pd,which shifts the d-band center of the Cu sites.展开更多
Methanol oxidation reaction （MOR） at Pt and Pt electrode surface deposited with various amounts of Ru （denoted as PtxRuy, nominal coverage y is 0.17, 0.27, and 0.44 ML） in 0.1 mol/L HClO4＋0.5 mol/L MeOH has been ...Methanol oxidation reaction （MOR） at Pt and Pt electrode surface deposited with various amounts of Ru （denoted as PtxRuy, nominal coverage y is 0.17, 0.27, and 0.44 ML） in 0.1 mol/L HClO4＋0.5 mol/L MeOH has been studied under potentiostatic conditions by in situ FTIR spectroscopy in attenuated-total-reflection con guration and di erential electro-chemical mass spectrometry under controlled flow conditions. Results reveal that （i） CO is the only methanol-related adsorbate observed by IR spectroscopy at all the Pt and PtRu electrodes examined at potentials from 0.3 V to 0.6 V （vs. RHE）; （ii） at Pt0.56Ru0.44, two IR bands, one from CO adsorbed at Ru islands and the other from COL at Pt substrate are detected, while at other electrodes, only a single band for COL adsorbed at Pt is observed; （iii） MOR activity decreases in the order of Pt0.73Ru0.27〉Pt0.56Ru0.44〉Pt0.83Ru0.17〉Pt; （iv） at 0.5 V, MOR at Pt0.73Ru0.27 reaches a current e ciency of 50% for CO2 production, the turn-over frequency from CH3OH to CO2 is ca. 0.1 molecule/（site sec）. Suggestions for further improving of PtRu catalysts for MOR are provided.展开更多
The electrochemical reduction of carbon dioxide was investigated on nickel and platinum electrodes in 0.5 mol dm^-3 KHCO3 solutions. The main products were formic acid and carbon monoxide during the electroreduction o...The electrochemical reduction of carbon dioxide was investigated on nickel and platinum electrodes in 0.5 mol dm^-3 KHCO3 solutions. The main products were formic acid and carbon monoxide during the electroreduction of CO2, and the Faradaic efficiency for this process depended on the characteristics of the electrode. At ambient temperature and pressure, the Faradaic efficiency was measured to be 8.6% and 2.5 % respectively for the production of formic acid and CO with Pt electrode at - 1.3V vs Ag/AgCl （saturated KCl）. At this same potential, the Faradaic efficiency was measured to be 8.9% and 1.7% respectively with Ni electrode. Tafel plots showed that the electrochemical reduction of CO2 was not limited by the mass transfer process in the range of -0.8 to - 1.2V vs Ag/AgCl （saturated KCl）.展开更多
基金supported by the National Natural Science Foundation of China(No.91545124 and No.21750110437)supported by the Chinese Academy of Sciences President’s International Fellowship Initiative(No.2017PM0049)。
文摘Bimetallic catalysts can improve CO2 reduction efficiency via the combined properties of two metals.CuPd shows enhanced CO2 reduction activity compared to copper alone.Using differential electrochemical mass spectrometry(DEMS)and electrochemical infrared(IR)spectroscopy,volatile products and adsorbed intermediates were measured during CO2 and CO reduction on Cu and CuPd.The IR band corresponding to adsorbed CO appears 300 mV more positive on CuPd than that on Cu,indicating acceleration of CO2 reduction to CO.Electrochemical IR spectroscopy measurements in CO-saturated solutions reveal similar potentials for CO adsorption and CO3^2-desorption on CuPd and Cu,indicating that CO adsorption is controlled by desorption of CO3^2-.DEMS measurements carried out during CO reduction at both electrodes showed that the onset potential for reduction of CO to CH4 and CH3OH on CuPd is about 200 mV more positive than that on Cu.We attribute these improvements to interaction of Cu and Pd,which shifts the d-band center of the Cu sites.
文摘Methanol oxidation reaction （MOR） at Pt and Pt electrode surface deposited with various amounts of Ru （denoted as PtxRuy, nominal coverage y is 0.17, 0.27, and 0.44 ML） in 0.1 mol/L HClO4＋0.5 mol/L MeOH has been studied under potentiostatic conditions by in situ FTIR spectroscopy in attenuated-total-reflection con guration and di erential electro-chemical mass spectrometry under controlled flow conditions. Results reveal that （i） CO is the only methanol-related adsorbate observed by IR spectroscopy at all the Pt and PtRu electrodes examined at potentials from 0.3 V to 0.6 V （vs. RHE）; （ii） at Pt0.56Ru0.44, two IR bands, one from CO adsorbed at Ru islands and the other from COL at Pt substrate are detected, while at other electrodes, only a single band for COL adsorbed at Pt is observed; （iii） MOR activity decreases in the order of Pt0.73Ru0.27〉Pt0.56Ru0.44〉Pt0.83Ru0.17〉Pt; （iv） at 0.5 V, MOR at Pt0.73Ru0.27 reaches a current e ciency of 50% for CO2 production, the turn-over frequency from CH3OH to CO2 is ca. 0.1 molecule/（site sec）. Suggestions for further improving of PtRu catalysts for MOR are provided.
基金Supported by the National Natural Science Foundation of China （No. 50408024） and Zhejiang Provincial Natural Science Fotmdation of China （No M203034 ）.
文摘The electrochemical reduction of carbon dioxide was investigated on nickel and platinum electrodes in 0.5 mol dm^-3 KHCO3 solutions. The main products were formic acid and carbon monoxide during the electroreduction of CO2, and the Faradaic efficiency for this process depended on the characteristics of the electrode. At ambient temperature and pressure, the Faradaic efficiency was measured to be 8.6% and 2.5 % respectively for the production of formic acid and CO with Pt electrode at - 1.3V vs Ag/AgCl （saturated KCl）. At this same potential, the Faradaic efficiency was measured to be 8.9% and 1.7% respectively with Ni electrode. Tafel plots showed that the electrochemical reduction of CO2 was not limited by the mass transfer process in the range of -0.8 to - 1.2V vs Ag/AgCl （saturated KCl）.
