Descriptor-based identification of bimetallic-derived catalysts for selective activation of ethane with CO₂

Abstract

Ethane–CO2 reaction over a wide range of bimetallic-derived catalysts was adopted to unravel the structure–function relationship over two types of representative structures.

Bimetallic-Derived Catalytic Structures for CO2-Assisted Ethane Activation

“…Conversely, when insufficient oxygen-induced driving force causes the alloy surface to remain stable under the reaction conditions, preferential C–C bond cleavage occurs, resulting in CO and H 2 production. A comparative investigation utilizing In-based bimetallic-derived catalysts (MIn, M = Pt, Ni, Cu, Co, Rh, and Pd, see Table S1) further validated the general correlation . Bimetallic-derived catalysts with high C 2 H 4 selectivity should exhibit strong oxygen binding, facilitating the formation of oxide/metal inverse interfaces under reaction conditions.…”

“…(d) Interplay of general descriptors guiding bimetallic-derived alloy or inverse interface for selective CO 2 –ethane upgrading. Adapted with permissions from ref (Copyright 2022 American Chemical Society) and ref (Copyright 2023 The Royal Society of Chemistry).…”

Reduction‐induced metal/oxide interfacial sites for selective CO2 hydrogenation

“…As demonstrated in Figure 3E, the similar X‐ray absorption near‐edge spectroscopy (XANES) feature of the Rh K‐edge with the Rh foil indicated a predominant metallic state of Rh over Rh/CeO 2 under reduction. The XANES results of all the In‐containing catalysts (Figure 3F–H), that is, Rh/In 2 O 3 , RhIn 3 /CeO 2 , and RhIn 3 /SiO 2 , also indicated the reduction of Rh as shown by the diminished white line; yet, compared with the Rh foil, the first resonance peak of XANES shifted to the lower energy along with an enhanced XANES intensity before 23235 eV, typically characteristic of the formation of RhIn alloys involving a charge transfer from In to Rh 27,35,36 . The In K‐edge XANES measurements over both RhIn 3 /CeO 2 (Figure 3I) and RhIn 3 /SiO 2 (Figure 3J) also showed significantly diminished white lines under reduction, which were closer to the In foil.…”

“…The XANES results of all the In-containing catalysts (Figure 3F-H), that is, Rh/In 2 O 3 , RhIn 3 /CeO 2 , and RhIn 3 /SiO 2 , also indicated the reduction of Rh as shown by the diminished white line; yet, compared with the Rh foil, the first resonance peak of XANES shifted to the lower energy along with an enhanced XANES intensity before 23235 eV, typically characteristic of the formation of RhIn alloys involving a charge transfer from In to Rh. 27,35,36 The In K-edge XANES measurements over both RhIn 3 /CeO 2 (Figure 3I) and RhIn 3 /SiO 2 (Figure 3J) also showed significantly diminished white lines under reduction, which were closer to the In foil. Thus, In over both catalysts was largely reduced but with a small amount of unreduced InO x species.…”

“…The M'O x /M inverse interfaces have been mainly generated by the H 2 ‐reduction‐induced strong metal−support interaction from a parent M/M'O x structure or by the chemical vapor deposition (CVD) of M'O x over the M substrate 10,18,19,22–25 . Our previous study reported a bimetallic‐derived principle that the formation of the M'O x /M inverse interface can be favorable when the reactive oxygen binding energy is greater than the alloy formation energy, which is the case with the PdM systems (M = Sn, In, and Ga) 11,21,26,27 . Different from the predefined M'O x /M structure by the CVD method, the bimetallic‐derived method undergoes thermodynamically favorable structural evolution to generate the inverse interface that is induced by reaction conditions.…”