In Situ Observation of C-C Coupling and Step Poisoning During the Growth of Hydrocarbon Chains on Ni(111)

Angew Chem Int Ed Engl. 2023 Jan 2;62(1):e202213295. doi: 10.1002/anie.202213295. Epub 2022 Dec 1.

Abstract

The synthesis of high-value fuels and plastics starting from small hydrocarbon molecules plays a central role in the current transition towards renewable energy. However, the detailed mechanisms driving the growth of hydrocarbon chains remain to a large extent unknown. Here we investigated the formation of hydrocarbon chains resulting from acetylene polymerization on a Ni(111) model catalyst surface. Exploiting X-ray photoelectron spectroscopy up to near-ambient pressures, the intermediate species and reaction products have been identified. Complementary in situ scanning tunneling microscopy observations shed light onto the C-C coupling mechanism. While the step edges of the metal catalyst are commonly assumed to be the active sites for the C-C coupling, we showed that the polymerization occurs instead on the flat terraces of the metallic surface.

Keywords: Fischer-Tropsch Synthesis; Heterogeneous Catalysis; Near-Ambient Pressure; Scanning Tunneling Microscopy.