Scientists at South Korea’s Dongguk University have synthesized an efficient catalyst for the oxygen evolution reaction — a component of the water-splitting process that produces hydrogen for fuel cells.
In a paper published in the journal Applied Catalysis B: Environmental, the researchers note that the catalyst, synthesized using molybdenum and ruthenium, exhibits high activity, reaction rates, and durability, opening doors to the cost-effective and large-scale production of next-generation catalysts.
The team led by Young-Kyu Han and Jitendra N. Tiwari also pointed out that the reduction of water to molecular hydrogen via the splitting water reaction is a key method for chemical energy storage aimed at addressing global energy challenges. However, issues like low catalyst activity, slow reaction speed, and catalyst degradation have posed challenges so far.
This is why the new study involved implanting ruthenium oxide into a two-dimensional molybdenum carbide to create a catalyst (Mo2TiC2Tx MXene) with high mass activity, turnover frequency, and durability. Calculations also indicated that the ruthenium sites had a strong affinity towards oxygen species, which enhanced the reaction.
Hydrogen and oxygen have diverse industrial applications, spanning clean fuel, power generation, chemical production, and life-support systems. They are also crucial in clean-energy transportation. However, more than 90% of hydrogen is in petroleum recovery and refining (47%) and ammonia production (45%).
“The need for decarbonizing the transportation sector makes hydrogen a promising alternative,” Tiwari, who is the lead author of the paper, said in a media statement. “Going ahead, fuel cell vehicles are expected to efficiently convert hydrogen into electrical energy, emitting only water, with longer driving ranges than battery electric vehicles. Additionally, hydrogen fuel cells do not need recharging and don’t degrade if hydrogen fuel is present, unlike in batteries.”
Tiwari pointed out that this study, thus, serves as a guide for researchers to create new catalysts for acidic water oxidation. It also sheds light on achieving cost-effective, large-scale catalyst production using diverse materials, such as dual-transition metal catalysts.