2021-025

About

Inventors have discovered a scalable Au-Pt-Bi electrocatalyst system that reduces the amount of energy required to generate hydrogen from solar energy when using glycerol as a fuel. Inventors have shown that a single commercial Si solar cell (Ecell < 0.630 V) can provide enough voltage to generate H2 from glycerol for days in the laboratory, where at least 1.7 V is required for the direct splitting of water. More importantly, this catalyst can reduce the system costs and complexity required to construct an 'artificial leaf,' as it reduces the number of semiconductor junctions required to generate the lower voltage for solar-to-hydrogen energy conversion using glycerol. A solar-to-hydrogen photoelectrochemical device can be built from a single semiconductor. Glycerol is a waste product of the biodiesel industry, so this invention contributes to the economics of biodiesel formation as well. The inventors have been studying the electrocatalytic transformation of glycerol as an energy source for fuel-forming electrochemical reactions like hydrogen evolution or CO2 reduction. Glycerol is electrochemically easier to oxidize than water (to O2) and is a waste stream for the biodiesel industry looking for routes to valorization. Inventors have recently published a paper on an Au-Pt catalyst system that can improve the oxidation of glycerol over the monometallic electrocatalysts. Therefore, Au is more stable than Pt, but requires a higher applied potential for the same current density. Inventors found a simple approach to synthesizing these electrocatalysts and then characterized the performance to find that we had improved the longevity of an electrode that performed like Pt. Inventors also noted some electronic effects that could explain the observation of improved electrocatalysis on the mixed-metal electrodes.