A MOF-supported Pd1–Au1 dimer catalyses the semihydrogenation reaction of acetylene in ethylene with a nearly barrierless activation energy
Jordi Ballesteros–Soberanas, Nuria Martín, Matea Bačić, Estefanía Tiburcio, Marta Mon, Juan Carlos Hernández‐Garrido, Carlo Marini, Mercedes Boronat, Jesús Ferrando–Soria, Donatella Armentano, Emilio Pardo, Antonio Leyva‐Pérez
Abstract
Abstract The removal of acetylene from ethylene streams is key in industry for manufacturing polyethylene. Here we show that a well-defined Pd 1 –Au 1 dimer, anchored to the walls of a metal–organic framework (MOF), catalyses the selective semihydrogenation of acetylene to ethylene with ≥99.99% conversion (≤1 ppm of acetylene) and >90% selectivity in extremely rich ethylene streams (1% acetylene, 89% ethylene, 10% H 2 , simulated industrial front-end reaction conditions). The reaction proceeds with an apparent activation energy of ∼1 kcal mol –1 , working even at 35 °C, and with operational windows (>100 °C) and weight hourly space velocities ( $$66{,}000\,{\mathrm{ml}}\,{\mathrm{g}}^{-1}_{\mathrm{cat}}\,{\mathrm{h}}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>66</mml:mn> <mml:mo>,</mml:mo> <mml:mn>000</mml:mn> <mml:mspace/> <mml:mi>ml</mml:mi> <mml:mspace/> <mml:msubsup> <mml:mrow> <mml:mi>g</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>cat</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace/> <mml:msup> <mml:mrow> <mml:mi>h</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> ) within industrial specifications. A combined experimental and computational mechanistic study shows the cooperativity between both atoms, and between atoms and support, to enable the barrierless semihydrogenation of acetylene.