High Purity H2 from Sunlight via a Unique Combination of Novel Photodiodes and Membranes

Precision Combustion, Inc. (PCI) together with University of Michigan (UMich) experimentally confirmed the capability of one-step solar water splitting to H2 and O2 and the potential for subsequent PEM quality H2 generation via a unique membrane architecture. The disruptive photodiode approach does not require the use of electricity or conductive electrolyte, as required for electrolysis. The novel membrane uses a passive approach to separate H2 and also avoids the needs for electricity. Maturation of the approach will support resource-scavenging in the battlefield to minimize logistic fuel supply burden and highlights the potential for direct onsite H2 generation, without the need for electricity, as long as water and sunlight are available. Preliminary tests indicated the ability to use greywater as a resource. Pathways for increasing solar to hydrogen efficiency were demonstrated. Production rates of 3x greater than the Phase I target was observed. Designs for scaling-up to 1 kg H2/day were also identified. During Phase II, remaining challenges will be addressed and the H2 production and separation design matured. These include maximizing photodiode efficiency, quantifying greywater suitability, improving membrane selectivity and durability, scaling up the design for practical applications, developing a standalone system with minimal parasitic power needs and all balance of plant components, and identifying cost and manufacturing viability.