Decoupled catalytic hydrogen evolution from a molecular metal oxide redox mediator in water splitting

The electrolysis of water using renewable energy inputs is being actively pursued as a route to sustainable hydrogen production. Here we introduce a recyclable redox mediator (silicotungstic acid) that enables the coupling of low-pressure production of oxygen via water oxidation to a separate, catalytic hydrogen production step outside the electrolyzer that requires no post-electrolysis energy input. This approach sidesteps the production of high-pressure gases inside the electrolytic cell (a major cause of membrane degradation) and essentially eliminates the hazardous issue of product gas crossover at the low current densities that characterize renewables-driven water-splitting devices. We demonstrated that a…

• RS
  Royal Society
• UO
  University of Glasgow
• WF
  Wolfson Foundation
• KN
  Kavli Nanoscience Institute, California Institute of Technology
• EA
  Engineering and Physical Sciences Research Council

  Awards: EP/K023004/1, EP/J015156/1, EP/J00135X/1
• AR
  Army Research Office