Lactic acid is used in food, pharmaceuticals and the production of polylactic acid, a biodegradable polymer. It is commonly made through fermentation, which requires controlled conditions and can take considerable time, while chemical production can depend on fossil-derived feedstocks. Metal–organic frameworks, or MOFs, offer another approach because their porous structures contain metal sites that can catalyze reactions. Yet previous MOF systems have generally produced modest lactic acid yields from glucose in water. Turning raw biomass into lactic acid presents an additional challenge because its carbohydrates must first become accessible for conversion.
A study (DOI: 10.48130/scm-0026-0027) published in Sustainable Carbon Materials on 14 September 2026 by Jianjian Wang's team, Chongqing University, reports that adding salicylic acid during catalyst synthesis created defects that improved glucose-to-lactic-acid production.
The team prepared a series of MOF-74(Ni) catalysts by replacing part of the usual organic linker with salicylic acid, then compared them with an unmodified catalyst. X-ray diffraction and microscopy showed that moderate modification preserved the framework’s main structure, although its crystallinity and particle shape changed. X-ray photoelectron spectroscopy and electron paramagnetic resonance provided evidence of more oxygen vacancies in the modified material. The researchers linked these defects to nickel sites with fewer coordinating bonds, which could help catalyze glucose conversion. In tests using 100 milligrams of glucose in 10 milliliters of water, the best-performing catalyst, MOF-74(Ni)-50SA, achieved 99.5% glucose conversion and a 51.7% lactic acid yield at 170 °C in four hours. Reducing the glucose amount to 50 milligrams raised the yield to 68.7%, showing that substrate concentration strongly affected the outcome. Kinetic analysis found an apparent activation energy of 69.6 kilojoules per mole with MOF-74(Ni)-50SA, compared with 79.3 kilojoules per mole for the unmodified catalyst. Tests with reaction intermediates suggested that the modified catalyst mainly improved the early conversion of glucose into compounds that can subsequently form lactic acid. It remained active across five reuse cycles, with glucose conversion above 97% and lactic acid yield above 40% in each cycle, although the yield declined by about ten percentage points by the fifth. In separate raw-biomass tests, corn cobs gave a 62.8% lactic acid yield at 170 °C after four hours; pine needles gave 5.6% under those conditions and 22.4% after a longer reaction at 190 °C. The difference highlights how feedstock structure can affect conversion.
The study shows that adjusting a metal–organic framework’s linkers can create defects that improve the conversion of glucose into lactic acid. The catalyst also produced lactic acid from raw biomass and remained active through five reuse cycles, although its yield declined over time. The lower yield from pine needles than from corn cobs shows that feedstock properties matter. Further work will need to test how the catalyst performs with more concentrated feedstocks and during extended use before its practical potential can be assessed.
###
References
DOI
10.48130/scm-0026-0027
Original Source URL
https://doi.org/10.48130/scm-0026-0027
Funding information
This work has been financially supported by Chongqing Human Resources and Social Security Bureau Project (cx2024049), Xinjiang Key Laboratory of New Energy and Energy Storage Technology (Xinjiang Institute of Technology Open Science Project, XJNEESYB202602), Sangruo (Xiamen) Perovskite PV Research Institute Co., Ltd. (H20240351), and Guangzhishui (Dali) Environmental Protection Co., Ltd. (H20251737).
About Sustainable Carbon Materials
Sustainable Carbon Materials (e-ISSN 3070-3557) is a multidisciplinary platform for communicating advances in fundamental and applied research on carbon-based materials. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon materials around the world to deliver findings from this rapidly expanding field of science. It is a peer-reviewed, open-access journal that publishes review, original research, invited review, rapid report, perspective, commentary and correspondence papers.