In addition to ethylene and ethane, C 4 products such as butane, 1-butene, 2-cis-butene, and 2-trans-butene, are formed during the acetylene hydrogenation. The selectivity towards C 4 products is lower than the selectivity towards ethylene or ethane (S C4 < 0.2). However, the formation of C 4 products indicates the tendency of carbon-carbon bond formation, and thus the tendency of forming acetylene oligomers, often referred to as green oil. These oligomers can accumulate on the surface of the material leading to the loss of activity (deactivation) typically at long t OS . In order to get insights on the processes that lead to oligomer formation and thus to catalyst deactivation, we also trained a SISSO model for S C4 by using the 539 data points belonging to the SG associated to high acetylene conversion. This model is noted in Eq. 7 (see further details in ESI).