Solar-pumped Ce:Nd:YAG lasers for efficient and rapid hydrogen extraction from aqueous ammonia under ambient condition without catalyst

Hydrogen (H2) is vital for a renewable society. However, H2 is flammable and inconvenient for transport. Therefore, in situ H2 extraction from aqueous ammonia (NH3) is an effective solution.
In 2024, Yan et al. [1] reported an ultrafast method for H2 extraction from ammonia-water by a 5 W low-efficiency pulsed lamp-pumped Nd:YAG laser at room temperature and ambient pressure without catalyst. H2 yield of 68.1 mg/h was realized, which was far higher than that by most H2 reactions under ambient conditions.

       We propose here a 130 W high-efficiency pulsed solar laser approach by pumping sequentially 2 four-beam Ce:Nd:YAG laser heads. A dichroic mirror will reflect 350 - 900 nm concentrated solar power, through the central hole of a 1.73 m2 parabolic mirror, to a rotating mirror, by which the 2 laser heads will be sequentially pumped during 200 ms, generating 10 ns laser pulses of several hundred mJ energy, at 50 Hz repetition rate, which will be applied to 8 H2 reactors by optical fibers. H2 yield of 9.2 g/h can be expected. Future scaling to 26 solar laser heads will boost the H2 yield to 119.6 g/h, most hopefully enabling in situ H2 fuel-cell vehicle charging stations.