Avoiding plastics altogether is a more sustainable choice, but given the pervasiveness of fossil-fuel derived plastics in our everyday lives, it’s a tough ask.
Wen-Qing Li, a Research Scientist at A*STAR’s Institute of High Performance Computing (IHPC), gave the example of light olefin such as ethylene—a simple molecule often derived from petroleum or natural gas—found in applications that include packaging, textiles and automotive components.
Thankfully, there are cleaner alternatives for making light olefins. Organic food waste and sewage produce hydrogen and carbon monoxide as it decomposes. Known as syngas, this mixture can be transformed into light olefins via specific catalyst-driven chemical reactions.
Sustainability research efforts are currently centred on optimising syngas to light olefin reactions by boosting efficiency and preventing the release of unwanted by-products such as methane.
Li and Jia Zhang, corresponding author of the study, noted that finding the best catalysts for these reactions can have far-reaching industry benefits: “Companies with optimised ethylene production processes can operate more cost-effectively and improve product quality, giving them a competitive edge in the market.”
Teaming up with collaborators from A*STAR’s Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Li and the researchers studied subtle and relatively unexplored chemical changes in iron carbide catalysts and how these impacted ethylene formation reactions.
Taking an out-of-the-box experimental approach, the researchers used density functional theory simulations to examine the chemical dynamics on the surface of iron carbide at a high resolution. They were particularly interested in the hydrogenation and mobility of surface carbon atoms during ethylene formation.
The study revealed never-before-seen insights into the intricate catalytic processes, including the observation that increasing the positive charge of iron atoms enhances the activity and selectivity for ethylene formation over methane. Li and colleagues also discovered that the movement of partially hydrogenated carbon intermediates on the iron carbide surface improved the overall reaction efficiency.
Li said that these findings contribute to broader efforts in making chemical processes more sustainable and less dependent on fossil fuels. Given the complex reaction scenarios on the iron carbide surface, the team has extended simulations incorporating advanced computational techniques planned to delve deeper into the catalyst’s reaction behaviours.
The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing (IHPC) and the Institute of Sustainability for Chemicals, Energy and Environment (ISCE2).