Researchers from China and Singapore have developed a new method that uses sunlight and biomass to produce green hydrogen at lower cost, while also creating another useful chemical in the process, reports gasworld.
The new technique uses sugars obtained from biomass such as agricultural waste cellulose. These sugars are converted into hydrogen and formate at the same time. The researchers said this combined process can reduce energy use compared to traditional solar methods that produce hydrogen only by splitting water.
In conventional solar electrolysis, a large amount of energy is required for a reaction that produces oxygen. In the new method, the oxidation of sugars replaces this step, lowering the overall energy demand.
To make the process more efficient, the research teams used a catalyst made from cobalt mixed with copper. This catalyst helps the sugar-based reaction take place more easily than the reactions used in standard electrolysis.
The experiment was carried out in a simple reactor without a separating membrane and was powered entirely by sunlight. According to the researchers, the system produced more than 500 micromoles of hydrogen per hour for each square centimetre of active surface area.
Although the total amount of hydrogen produced is small, the researchers explained that early-stage systems are measured by output per unit area rather than total volume. On this basis, the production rate is considered relatively high.
The results suggest that solar-powered systems combining hydrogen production with the use of biomass could be expanded in the future. Earlier laboratory studies have explored similar ideas using alcohols and other organic materials, but many of those relied on external electricity instead of sunlight alone.
The researchers noted that the technology is still at an early stage. Challenges remain in ensuring the catalyst lasts for long periods, performs well under changing sunlight, and works with more complex and less refined biomass materials.
Even so, the method is based on solid catalysts and sunlight, both of which can be scaled up. The membrane-free design may also help reduce costs and simplify the system if the technology moves beyond laboratory research.
