Outdoor sunlight-driven scalable water-gas shift reaction through novel photothermal device-supported CuOx/ZnO/Al2O3 nanosheets with a hydrogen generation rate of 192 mmol g−1 h−1

Abstract

Hydrogen generation from water-gas shift (WGS) reaction requires the import of secondary energy, making it unsuitable for large scale applications. Herein, we present a new scalable system consisting of new photothermal device and catalysts that can produce hydrogen via the WGS reaction with zero additional energy import. The new photothermal device based on a chromium film can completely absorb sunlight, fully convert sunlight to heat energy and localize the heat energy synergistically, which makes a high temperature of 305 °C under one standard sunlight irradiation. The catalysts are scalable CuO_x/ZnO/Al₂O₃ nanosheets (2D CuZnAl) with high WGS activity, which were synthesized via the surfactant effect of boric acid. The 2D CuZnAl could be heated to 297 °C under one standard solar irradiation with the new photothermal device. This new system shows a hydrogen production rate of 192.33 mmol g⁻¹ h⁻¹ under one standard sunlight irradiation, 402 times to that of the current record of the one sunlight-driven WGS reaction. Moreover, this new system could be amplified to industrial scale with 4.2 m² of irradiated area and was able to generate 6.60 m³ of hydrogen from the WGS reaction solely driven by outdoor sunlight in the daytime of spring as well as realized a zero emission of CO₂ with the help of a greenhouse agriculture. This study introduces a scalable, highly efficient zero CO₂ emission and stable route of outdoor sunlight-driven hydrogen generation from the WGS reaction.