Scientists Develop Breakthrough Catalyst for Clean Propane Conversion

Propane dehydrogenation (PDH) is a chemical process that requires a large input of heat, typically needing temperatures above 600°C when carried out using traditional thermo-catalytic methods, the journal Nature Chemistry reported.

These high temperatures pose several issues, including high energy usage, degradation of the catalyst through sintering, and the buildup of carbon deposits known as coke. Scientists have long sought ways to overcome these limitations and carry out PDH at or near room temperature, which remains a key challenge in the field of catalysis.

A new study published in Nature Chemistry offers a promising solution. Led by Prof. Tao Zhang and Prof. Aiqin Wang from the Dalian Institute of Chemical Physics at the Chinese Academy of Sciences (CAS), in collaboration with Prof. Yi Gao’s team at the Shanghai Advanced Research Institute of CAS, the researchers introduced a novel approach.

They developed a water-assisted PDH process that uses a copper single-atom catalyst (SAC) and is driven by a combination of light and heat, known as photo-thermo catalysis. This method enables efficient conversion of propane into propylene at much lower temperatures than previously possible.

By using a Cu1/TiO2 SAC, researchers achieved PDH under near-ambient conditions in a water vapor atmosphere. In a continuous-flow fixed-bed reactor, the reaction temperature was reduced to just 50–80 °C, achieving a maximum reaction rate of 1201 μmol gcat-1 h-1.

Researchers revealed that Cu single atoms, water vapor, and light illumination all played essential roles in the propane-to-propylene conversion.

Through photocatalytic water splitting on the Cu1/TiO2 SAC, hydrogen and hydroxyl species were generated. Hydroxyl radicals subsequently adsorbed on the catalyst surface, abstracting hydrogen atoms from propane to form propylene and water. Water acted catalytically without being consumed. This mechanism fundamentally differs from traditional PDH and oxidative dehydrogenation of propane.

Furthermore, researchers demonstrated that the developed route could be extended to the dehydrogenation of other light alkanes, including ethane and butane. The reaction could even be directly driven by sunlight using the Cu1/TiO2 SAC.

“Our study not only provides a new way for PDH but also establishes a paradigm for conducting high-temperature reactions driven by solar energy,” said Prof. Xiaoyan Liu, one of the corresponding authors of the study.

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