Recently, a research team from the School of Science, Department of Frontier Sciences, Harbin Institute of Technology has made an important breakthrough in the field of anode electrocatalysis for hydrogen production by proton membrane water electrolysis, successfully solving the technical problem of the activity-stability trade-off of iridium nickel oxygen electrocatalysts. This scientific research result has injected strong impetus into the development of our country's clean energy technology. In this breakthrough, tungsten played a key role, opening up a new technical path for the future development of the green hydrogen industry.
Tungsten element picture
In the context of the global active pursuit of clean energy transformation, hydrogen energy, as an efficient and clean secondary energy source, has received widespread attention. Proton membrane water electrolysis hydrogen production technology has become one of the core technologies for future green hydrogen production with its unique advantages. It is environmentally friendly and produces almost no pollutants during the hydrogen production process; it has a high current density and can efficiently convert electrical energy into chemical energy; it has a fast response and can be adjusted in time according to changes in energy supply and demand; it also has the characteristic of resistance to fluctuations, suitable for direct coupling with fluctuating renewable energy sources such as wind and light, and effectively solves the problem of unstable renewable energy generation. However, this technology has always faced the problem of activity-stability trade-off in anode electrocatalysis, which limits its large-scale application and cost reduction.
Proton membrane water electrolysis hydrogen production experiment picture
In response to the above problems, the research team of Harbin Institute of Technology proposed an innovative strategy based on dual regulation. They found that by cleverly introducing iridium-oxygen-tungsten bridging groups into iridium-nickel-oxygen electrocatalysts, the catalyst surface reconstruction and the oxygen evolution reaction path can be precisely regulated and optimized. This discovery is like a key that opens the door to breaking through technical bottlenecks.
During the research process, the team overcame technical difficulties such as the insolubility of tungsten oxide and iridium oxide, and successfully achieved atomic-level uniform tungsten-oxygen doping of nano-iridium oxide by using nickel-assisted iridium-tungsten electrodeposition dealloying method. This breakthrough has laid a solid foundation for subsequent research.
Further studies have shown that the iridium-oxygen-tungsten bridging group significantly improves the performance of the catalyst through a dual-site synergistic mechanism. On the one hand, it effectively inhibits the participation of lattice oxygen in the reaction and avoids the attenuation of catalyst performance; on the other hand, through the charge compensation mechanism, it solves the problems of transition metal etching and increased oxidation state of iridium sites, and significantly enhances the stability of the catalyst. In addition, as a proton acceptor, the bridging oxygen promotes proton transfer in acidic electrolytes, relieves the restriction on the protonation and removal of key intermediates, and further improves the activity of the oxygen evolution reaction.
This research result not only achieves the dual improvement of electrochemical performance and stability of reconstructed iridium oxide-based catalysts, provides a more reliable catalyst for the practical application of proton membrane water electrolysis hydrogen production technology, but also provides valuable reference for the further design of low-cost and high-performance oxygen evolution catalysts for acid electrolysis
