IMPORTANCE OF BUFFER IN THE DESIGN AND STUDY OF SOLAR FUEL PRODUCTION SYSTEMS

摘要

The development of a device capable of generating a fuel, suchnas hydrogen or methanol, from solar energy remains quitenchallenging.1 Water oxidation is a significant bottleneck in either ofnthese systems and the interplay of all the necessary componentsnincluding catalysts, electrolyte, buffer, proton exchange membranes,netc. is not yet adequately understood.2 Since the reactions of waternsplitting and CO2 reduction are pH dependent, control of the pH withna buffer is essential. Reports on new catalysts for water oxidation,nwater reduction and CO2 reduction, often ignore or downplay the rolenbuffer has on the reactivity and stability of the catalyst and of thenother necessary components in the system. Careful, systematicnstudies are needed.3 The polyoxometalate water oxidation catalystnNa10[Co4(H2O)2(PW9O34)2] (Co4POM) serves as a exemplary casenwhere buffer affects not only the stability of a catalyst but also itsnreactivity.4 While the POM’s intrinsic stability is both pH and bufferndependent, the effect of its stability on water oxidation catalysis isnonly noticeable at longer time scales (> 3 hours).