2015学术论坛无机分组12

1、Re(bpy)(CO)3Cl催化二氧化碳电还原的动力学研究赵 羿复旦大学化学系2015.9.26复旦大学化学系第三届本科生学术科技论坛背景实验方法结果与讨论总结与展望CO2的利用循环伏安法电解质和溶剂的影响决速步的探讨总结汇报提纲未来工作背景实验方法结果与讨论总结与展望环境问题：二氧化碳排放*预计*预计*预计*预计单位:ppmIEA: 2014年全球CO2排放量达252亿吨！背景实验方法结果与讨论总结与展望二氧化碳的化学利用HCOOHCOCH4CO C2H4 HCOOHCH3OH CH3CH2OH sugarCH3COOHCO+H2hydrocarbonsCH3CH2OH CH3OH 电还原二

2、氧化碳：条件温和能量利用效率高易于控制背景实验方法结果与讨论总结与展望Re(bpy)(CO)3Cl催化二氧化碳电还原背景实验方法结果与讨论总结与展望实验装置RefWorkCGasElectrochemical workstationPtPC三电极体系工作电极 (Work)参比电极 (Ref)辅助电极 (C)Glassy carbonAg/Ag+ (0.01M)Pt催化剂电解质溶剂溶液背景实验方法结果与讨论总结与展望不同溶剂与电解质组合DMF+TEABF4DMF+TBAPF6CH3CN+TEABF4CH3CN+TBAPF6Figure 1. Cyclic voltammograms of cro

3、ssover experiments of Electrolyte 1, Electrolyte 2, Solvent 1 and Solvent 2 under N2 and CO2. Catalyst: 0.5 mM Re(bpy)(CO)3Cl; scan rate: 0.1 V/s; electrolytes concentration: 100 mM; glassy carbon working electrode, Pt counter electrode, Ag/Ag+ reference electrode. (a) CVs with TBAPF6 and TEABF4 in

4、DMF. (b) CVs with TBAPF6 and TEABF4 in CH3CN. (c) CVs with TBAPF6 in DMF and CH3CN. (d) CVs with TEABF4 in DMF and CH3CN.acbd背景实验方法结果与讨论总结与展望反应机理的探究Figure 2. Proposed mechanism for electrochemical reduction of CO2 by Re(bpy)(CO)3Cl Figure 3. Cyclic voltammograms of reduction of CO2 with TEABF4 in DM

5、F. Catalyst: 0.5 mM Re(bpy)(CO)3Cl; scan rate: 0.1 V/s; electrolyte concentration: 100 mM; glassy carbon working electrode, Pt counter electrode, Ag/Ag+ reference electrode.Rate Limiting StepThe shift is 0.022 V with the scan rate of 0.1V/sapproximate time scale for the rate limiting step of 4.5 s-1

6、Shift of the second Peak 背景实验方法结果与讨论总结与展望动力学计算：催化速率常数Randles-Sevcik方程:icat=0.4463nFACRe (nFvDRe/RT)1/2 CO2N2icat - v1/2拟合Figure 4. Cyclic voltammograms and plot of ip1 vs v1/2 of scan rate change experiments.Catalyst: 0.5 mM Re(bpy)(CO)3Cl; electrolytes concentration: 100 mM; glassy carbon working e

7、lectrode, Pt counter electrode, Ag/Ag+ reference electrode.速率常数kcat的计算:icat=nFARe DRe1/2 kcat Table 1. Kinetic calculations for the reduction of carbon dioxide. Catalyst: 0.5 mM Re(bpy)(CO)3Cl; electrolytes concentration: 100 mM; glassy carbon working electrode, Pt counter electrode, Ag/Ag+ referenc

8、e electrode. (a) CVs with TBAPF6 in CH3CN.(b) CVs with TEABF4 in CH3CN. (c) CVs with TBAPF6 in DMF. (d) CVs with TEABF4 in DMFSolutionElectrolyteSolventDRe(10-5cm2s-1)kcat(s-1)RLS timescale(s-1)aTBAPF6CH3CN2.24.50.68bTEABF4CH3CN2.436-cTBAPF6 DMF1.44.7-dTEABF4DMF1.62216.671. 溶剂和电解质对催化效率的影响：CH3CN和TEABF42. 决速步假设：CO2对Cl的取代3. 验证：动力学计算背景实验方法结果与讨论总结与展望总结与展望1. kr的理论推导和模拟计算2. CO2 浓度