Electronic modulation of metal-support interactions improves polypropylene hydrogenolysis over ruthenium catalysts

• Published in: Nature communications Vol. 13; no. 1; pp. 5186 - 11
• Main Authors: Kots, Pavel A., Xie, Tianjun, Vance, Brandon C., Quinn, Caitlin M., de Mello, Matheus Dorneles, Boscoboinik, J. Anibal, Wang, Cong, Kumar, Pawan, Stach, Eric A., Marinkovic, Nebojsa S., Ma, Lu, Ehrlich, Steven N., Vlachos, Dionisios G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.09.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 140/133; 140/146; 147/137; 639/301/299/1013; 639/638/77/885; 639/638/77/887; Ammonia; Catalysts; Circular economy; Density functional theory; Deuterium; Humanities and Social Sciences; Hydrogen; Hydrogen storage; Hydrogenolysis; Laboratories; Lubricants; Magnetic resonance spectroscopy; multidisciplinary; Nanoparticles; NMR; NMR spectroscopy; Nuclear magnetic resonance; Plastic debris; Polyolefins; Polypropylene; Ruthenium; Science; Science (multidisciplinary); Solvents; Titanium dioxide
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-32934-5

Ruthenium (Ru) is the one of the most promising catalysts for polyolefin hydrogenolysis. Its performance varies widely with the support, but the reasons remain unknown. Here, we introduce a simple synthetic strategy (using ammonia as a modulator) to tune metal-support interactions and apply it to Ru deposited on titania (TiO 2 ). We demonstrate that combining deuterium nuclear magnetic resonance spectroscopy with temperature variation and density functional theory can reveal the complex nature, binding strength, and H amount. H 2 activation occurs heterolytically, leading to a hydride on Ru, an H + on the nearest oxygen, and a partially positively charged Ru. This leads to partial reduction of TiO 2 and high coverages of H for spillover, showcasing a threefold increase in hydrogenolysis rates. This result points to the key role of the surface hydrogen coverage in improving hydrogenolysis catalyst performance. Catalytic pathways of plastic waste valorization to lubricants are attractive avenues to foster circular economy. Tuning of catalyst electronic properties allows to significantly improve its activity due to boosted hydrogen storage on the surface.