TY - BOOK
T1 - Electrocatalysis for Sustainable Chemical Production
T2 - Testing and Analysis of Electrode Materials
AU - Davies, Bethan
PY - 2019
Y1 - 2019
N2 - Electrification of the chemical industry may result in the sustainable use of both material and energy resources for transport and everyday synthetic products. Chemical conversion by electrocatalysis is an environmentally friendly production method. Herein, electrocatalysis is used for chemical valorisation, converting simple molecules, methanol and CO, into a high-value chemical, dimethyl carbonate (DMC). Currently, DMC is produced by traditional catalysis methods under hazardous conditions. Electrocatalysis synthesis of DMC can be performed at room temperature and pressure with the driving force of the electrochemical potential. In this work, the methodology required for electrocatalyst testing and analysis was set up. Quantitative chemical analysis by headspace-gas chromatography-mass spectrometry (HS-GC-MS) for studying organic electrolyte solutions was developed and external reflection in situ infrared spectroelectrochemistry was optimised, to determine reaction efficiency, selectivity and stability of different electrode materials. By using of HS-GC-MS is is possible to determine the product concentrations in solution which allow for efficiency and selectivity analysis. Comparisons of efficiency allow the relative activities of catalysts to be reported, while spectroelectrochemistry probes the electrode-electrolyte interface to determine solution phase and adsorbed intermediates which is vital in the investigation of the mechanism. The combination of electrochemical, spectroelectrochemical and analytical methods have allowed studying the electrocatalytic syntheses of DMC on metallic electrodes, such as Pd, Au and Cu. The reaction selectivity and activity was analysed with regards to the hypothesised mechanism. The conversion of chemicals is complex especially where multiple products and intermediates can be formed, and this is highlighted by the differences in the reactivities of the metals: DMC is formed by homogeneous electrocatalysis with Cu, while Au and Pd catalysis the reaction heterogeneously. Au shows the highest activity for the synthesis, both in terms of efficiency and reaction rate. The electrode testing methodology can be applied to study other reactions. Development of such electrocatalysis systems and analyses are necessary steps forward in the sustainable production of chemicals.
AB - Electrification of the chemical industry may result in the sustainable use of both material and energy resources for transport and everyday synthetic products. Chemical conversion by electrocatalysis is an environmentally friendly production method. Herein, electrocatalysis is used for chemical valorisation, converting simple molecules, methanol and CO, into a high-value chemical, dimethyl carbonate (DMC). Currently, DMC is produced by traditional catalysis methods under hazardous conditions. Electrocatalysis synthesis of DMC can be performed at room temperature and pressure with the driving force of the electrochemical potential. In this work, the methodology required for electrocatalyst testing and analysis was set up. Quantitative chemical analysis by headspace-gas chromatography-mass spectrometry (HS-GC-MS) for studying organic electrolyte solutions was developed and external reflection in situ infrared spectroelectrochemistry was optimised, to determine reaction efficiency, selectivity and stability of different electrode materials. By using of HS-GC-MS is is possible to determine the product concentrations in solution which allow for efficiency and selectivity analysis. Comparisons of efficiency allow the relative activities of catalysts to be reported, while spectroelectrochemistry probes the electrode-electrolyte interface to determine solution phase and adsorbed intermediates which is vital in the investigation of the mechanism. The combination of electrochemical, spectroelectrochemical and analytical methods have allowed studying the electrocatalytic syntheses of DMC on metallic electrodes, such as Pd, Au and Cu. The reaction selectivity and activity was analysed with regards to the hypothesised mechanism. The conversion of chemicals is complex especially where multiple products and intermediates can be formed, and this is highlighted by the differences in the reactivities of the metals: DMC is formed by homogeneous electrocatalysis with Cu, while Au and Pd catalysis the reaction heterogeneously. Au shows the highest activity for the synthesis, both in terms of efficiency and reaction rate. The electrode testing methodology can be applied to study other reactions. Development of such electrocatalysis systems and analyses are necessary steps forward in the sustainable production of chemicals.
UR - https://rex.kb.dk/permalink/f/h35n6k/KGL01012061355
M3 - Ph.D. thesis
BT - Electrocatalysis for Sustainable Chemical Production
PB - Department of Chemistry, Faculty of Science, University of Copenhagen
ER -