Enhanced Selectivity of the Propylene Epoxidation Reaction on a Cu Monolayer Surface via Eley‐Rideal Mechanism

Abstract

The aerobic oxidation of propylene to selectively achieve propylene oxide (PO) is a challenging reaction in catalysis. Therefore, an active catalyst which shows enhanced PO selectivity is extremely desired. In the present investigation, an attempt has been made to explore the catalytic activity of a mono‐atomically thin two‐dimensional (2D) hexagonal (HX) Cu layer for selective propylene epoxidation using molecular O2 with the aid of density functional theory calculations. The results reveal that the conversion of propylene to PO via Eley‐Rideal mechanism is an exoergic and barrierless reaction on the O2 pre‐adsorbed Cu monolayer. The Pauli energy component plays a decisive role for barrierless reaction whereas the electrostatic and orbital contribution governs the energetic stability of PO. Car‐Parrinello molecular dynamics (CPMD) simulation reinforces the outcomes of climbing image nudged elastic band (CI‐NEB) calculation. Further, the formation of oxametallacycle OMC‐2 (0.47 eV) is kinetically favourable over OMC‐1 (0.87 eV) and AHS (0.50 eV) on O pre‐adsorbed 2D HX Cu. Interestingly, the energy barrier for the conversion of OMC‐2 to PO (0.70 eV) is considerably low in comparison with the acetone formation (0.90 eV). Therefore, it is worth to mention that the 2D HX Cu surface provides a promising platform for selective propylene epoxidation.

Structure, stability, and electronic and optical properties of TMDC–coinage metal composites: vertical atomically thin self-assembly of Au clusters

“…39,40 2D metal flatlands have received widespread research attention from the scientific community in the past few years. [41][42][43][44][45][46][47][48][49][50][51][52][53][54] Significant efforts have been made to probe the structure and stability of ultrathin 2D metal layers. 43,[55][56][57][58][59][60][61] A recent study by Koskinen and co-workers revealed that the metals can be stabilized as 2D patches inside the pores of graphene and Cu forms the best stable patch among the 45 elements studied.…”

Electronic and photophysical properties of an atomically thin bowl-shaped beryllene encapsulated inside the cavity of [6]cycloparaphenylene (Ben@[6]CPP)

“…Much research is currently being undertaken into the stability, properties, and applications of metallic layers, particularly since the potential of graphene was first identified. [27][28][29][42][43][44][45][46][47][48] Despite many advances, the field of ultrathin metals is still in its infancy and there remains plenty of opportunity for new discoveries because the periodic table is mostly full of metallic elements. 16,49 Even though theoretical simulations have predicted the stability of the freestanding monoatomically thin membranes of metals, the experimental realization of these extended layers is often challenging.…”

“…Much research is currently being undertaken into the stability, properties, and applications of metallic layers, particularly since the potential of graphene was first identified. 27–29,42–48 Despite many advances, the field of ultrathin metals is still in its infancy and there remains plenty of opportunity for new discoveries because the periodic table is mostly full of metallic elements. 16,49…”

A prospectus for thickness dependent electronic properties of two‐dimensional metals using density functional theory calculation

“…Of the 45 elemental metals studied to probe the stability limits of 2D patches embedded inside the pore of graphene, it is found that Cu forms the most stable 2D patch followed by Zn, Ag and Au [34]. These studies have further influenced the scientific community to investigate the structure, stability, properties, and applications of the freestanding 2D metal membranes without skeletal support [26,28,32,35,[53][54][55][56][57][58][59]. A recent theoretical work carried out to explore the magnetic behavior of 2D metals showed that the magnetism is enhanced when the thickness of the metal is reduced to a mono atomically thin membrane [53].…”

“…The catalytic performance of atomically thin 2D Pt and Cu monolayers studied using density functional theory (DFT) calculation reveals that Pt monolayer is a potential catalyst for oxygen reduction reaction and 2D Cu(111) monolayer acts as a promising surface for selective CO 2 reduction [25, 60]. The enhanced selectivity for propylene epoxidation to give propylene oxide via Eley‐Rideal mechanism on Cu monolayer is recently predicted by means of DFT studies [61]. Further, the dynamical and mechanical stability, electronic and magnetic properties of 2D HX Lanthanides were theoretically explored in our recent work [62].…”