Polyethylene hydrogenolysis to liquid products over bimetallic catalysts with favorable environmental footprint and economics
Iris Nogueroles-Langa, Yuzhen Ge, Cecilia Salah, Shibashish D. Jaydev, Jordi Morales‐Vidal, Pol Sanz Berman, Henrik Eliasson, Rolf Erni, Gonzalo Guillén‐Gosálbez, Núria López, Antonio J. Martín, Javier Pérez‐Ramírez
Abstract
Assessing the sustainability of plastic chemical recycling requires realistic feedstocks and catalysts designed within sustainability-led frameworks (Plastic-to-X). We link catalyst design and systems analysis to study hydrogenolysis of high-density polyethylene (virgin and bottle caps; Mw = 100–200 kDa). We report Ru–Ni alloy nanoparticles (3–4 nm) supported on titania that yield up to 55% liquid C6–C45 products under optimized conditions, whereas monometallic Ru produces virtually no liquids Operando spectroscopy and simulations reveal structure sensitivity: backbone scission follows dehydrogenation and hydrogenation cycles at defective alloy sites formed in situ. Integrating these mechanistic insights with life cycle and techno-economic analyses indicates profitable processing of plastic caps over the optimal catalyst (2.5 wt% Ru, 5 wt% Ni) with substantially lower CO2 emissions even when using green H2. Furthermore, within the Plastic-to-X framework, we identify a minimum average chain length threshold of C11 for product distributions as a critical design metric to reconcile environmental and economic objectives. Proving sustainable chemical plastic recycling must rely on realistic feedstocks and sustainability-driven catalyst design. Here, the authors report titania-supported Ru–Ni alloy nanoparticles achieving up to 55% liquid (C6 to C45) products for low-carbon and profitable polyethylene hydrogenolysis and determine a metric for sustainable product distributions.