Highly Networked Platinum–Tin Nanowires as Highly Active and Selective Catalysts towards the Semihydrogenation of Unsaturated Aldehydes

Abstract

The selectiveh ydrogenation of a,b-unsaturated aldehydes to unsaturated alcohols is an important processf or many industrial applications, whereas the realization of excellent conversion efficiency and selectivity remains as ignificant challenge. Herein, we report the preparation of ac lass of networked Pt-Sn nanowires (Pt-Sn NWs) for the selective hydrogenation of unsaturated aldehydes to the desired unsaturated alcohols. The optimized Pt 1.5 Sn NWs delivered ahigh conversion efficiency (98.1 %) for the hydrogenation of cinnamaldehyde (CAL) and excellent selectivity to cinnamyl alcohol (COL) (90.6 %); thus, they outperformed Pt 1.5 Sn nanoparticles (NPs) as wella s Pt NPs. The high performance of the Pt 1.5 Sn NWsw as expanded to the hydrogenation of other a,b-unsaturateda ldehydes. X-ray photoelectrons pectroscopy revealed that ah ighr atio of metallicP ti nt he Pt 1.5 Sn NWs boosted the conversion of CAL and that ah igh Sn content favored the hydrogenation of the C=Ob ond, both of which lead to excellent activity and selectivity.

Guidelines to Achieving High Selectivity for the Hydrogenation of α,β-Unsaturated Aldehydes with Bimetallic and Dilute Alloy Catalysts: A Review

“…Surface science and DFT studies have shown that the adsorption of the unsaturated aldehydes is weaker on SnPt surfaces compared to monometallic Pt surfaces, and their adsorption geometries are also modified, except in the case of acrolein. 134 Sn 0.4 Pt 0.6 was found to be the optimal composition: lower Sn content led to a higher activity but a lower selectivity. Two main trends were established: (i) the higher the metallic Pt 0 content, the higher the conversion; and (ii) the higher the Sn content, the higher the selectivity due to a charge transfer from Sn to Pt.…”

“…While moderate to high selectivity was generally reported at high conversions of cinnamaldehyde 86,100,[147][148][149][157][158][159][211][212][213][214][215][216][217][218][219] and furfural, 213,220 the hydrogenation of citral 221 and smaller aldehydes, such as crotonaldehyde 85,116,142,214,222,223 and acrolein, 213 have usually exhibited very low selectivity to the unsaturated alcohols. bimetallics for the hydrogenation of crotonaldehyde, 85,100,116,133,134,142,147,214,222,223 cinnamaldehyde, 86,100,133,134,[147][148][149]155,[157][158]…”

“…The hydrogenation pathways were further mapped out on Pt N (N = 6-18). 216,[251][252][253] Pt/graphene showed high selectivity to cinnamyl alcohol, 216 In reactor studies, promotion of Pt with a secondary metal, such as Re, 225 Fe, 147,159 Co, 148,149,158 Zn, 159,221 Sn, 133,134,224,227 and Ge, 224 has led to high selectivity at high conversion, even for crotonaldehyde hydrogenation, due to an electron transfer and/or the formation of the electrophilic sites (Fig. 9a).…”

“…On the other hand, SnPt alloys supported on carbon showed higher selectivity to crotyl alcohol with increasing Sn concentration, in agreement with reactor studies. 134 To understand the role of the oxidic species, SnPt(111) alloys were oxidized to form surface SnO x :…”

Synergism of Pt nanoparticles and iron oxide support for chemoselective hydrogenation of nitroarenes under mild conditions

“…However, large scale application of Pt-based catalysts is still limited by their high cost [8][9][10][11]. Moreover, active Pt sites cannot discriminate the differences of functional groups, causing a low catalytic selectivity [12][13][14]. Take the hydrogenation of nitroarenes as an example, nitro groups and other reducible groups (e.g., C=C, C=O, -X, etc.)…”