Highly Efficient Polyolefin Hydrogenolysis Enabled by a Single-Site Organo-Tantalum Catalyst on a Super-Acidic Support

The novel electrophilic organo-tantalum catalyst AlS/TaNp () (Np = neopentyl) is prepared by chemisorption of the alkylidene Ta(CHtBu)Np onto highly Brønsted acidic sulfated alumina (AlS). The proposed catalyst structure is supported by EXAFS, XANES, ICP, DRIFTS, and SSNMR measurements and is in good agreement with DFT analysis. Adsorbate is a highly effective catalyst for the hydrogenolysis of linear and branched hydrocarbons, ranging from C2 to polyolefins. To the best of our knowledge, 𝟏 exhibits the highest polyolefin hydrogenolysis activity (9,200 (CH₂ units)·mol(Ta)⁻¹·h⁻¹ at 200 °C/17 atm H₂) reported to date in the peer-reviewed literature. Unlike the AlS/ZrNp₂ analog, the Ta catalyst is more thermally stable and has multiple potential reaction pathways for C-C bond activation. For hydrogenolysis, AlS/TaNp₃ is effective for a wide variety of pre- and post-consumer polyolefin plastics and is not significantly deactivated in the presence of standard polyolefin additives.