Theoretical studies of acrolein hydrogenation on Au20 nanoparticle

Abstract

Gold nanoparticles play a key role in catalytic processes. We investigated the kinetics of stepwise hydrogenation of acrolein on Au20 cluster model and compared with that on Au(110) surface. The rate-limiting step barrier of CC reduction is about 0.5 eV higher than that of CO hydrogenation on Au(110) surface. On Au20 nanoparticle, however, the energy barrier of the rate-determining step for CC hydrogenation turns out to be slightly lower than the value for the CO reduction. The selectivity difference on the two substrate models are attributed to different adsorption modes of acrolein: via the CC on Au20, compared to through both CC and CO on Au(110). The preference switch implies that the predicted selectivity of competitive hydrogenation depends on substrate model sensitively, and particles with more low-coordinated Au atoms than flat surfaces are favorable for CC hydrogenation, which is in agreement with experimental result.

Theoretical Studies of Species Related to Acrolein Hydrogenation

“…According to our recent work on Au(110) [9] and Au 20 [11], radicals bind to substrates via atoms with an unpaired electron favorably.…”

“…Recently Claus et al [4][5][6]. found that the conventionally catalytically inert gold exhibits unexpected activity for the selective hydrogenation of a, b-unsaturated aldehydes to allyl alcohols, which re-initiates interests on hydrogenation of a, b-unsaturated aldehydes [6][7][8][9][10][11][12]. Acrolein (CH 2 =CH-CH=O) is the first member of a, b-unsaturated aldehyde and its selective hydrogenation to allyl alcohol is most difficult because there are no substitution groups on the carbon atoms of the C=C bond.…”

“…For this reason it is often used as a model system for studying selective hydrogenation of a, b-unsaturated aldehyde both experimentally and theoretically [6,8]. As far as we know, theoretical studies mainly devoted to adsorption and reactions of acrolein and various hydrogenated species on metal or alloy surface [8,[10][11][12], and less attention is paid to the molecular structures, stability and transformation of the species derived from acrolein hydrogenation.…”

Adsorption of small molecules on helical gold nanorods: A relativistic density functional study

“…[25] For CH 2 @CHACH@O adsorption on small gold clusters, CH 2 @CHACH@O preferentially interacts with the gold cluster via the C@C group rather than the C@O group. [26,27] For both H 2 S and SO 2 adsorption on small gold clusters (which are planar), the sulfur atom is in the same plane and these molecules preferentially adsorb at a single low-coordination gold atom on the gold cluster. [28][29][30][31][32][33] Although impressive progress has been achieved in understanding the adsorption of small molecules on small gold clusters, computational studies for large gold clusters are generally lacking.…”

Acrolein Adsorption on Gold Clusters, A Theoretical Study of Conjugation Effect on C=C and C=O Interaction with Au Clusters

“…Although there are many studies in the literature about adsorption of isolated C=C and C=O groups on gold clusters, studies of AC where the C=C and C=O groups are conjugated on gold clusters are relatively fewer [28]. As the adsorption configuration plays a key role in determining hydrogenation selectivity for a, b-unsaturated aldehydes, herein we systematically studied adsorption of AC on the Au n (n = 1-5) clusters.…”