Au‐Promoted Pt nanoparticles supported on MgO/SBA‐15 as an efficient catalyst for selective oxidation of glycerol

Abstract

A systematic study of Au-promoted and unpromoted Pt/MgO/SBA-15 catalyst is developed to separate the promoter effect from electron transfer effect between Au and Pt. Multi-characterizations revealed that Au and Pt metals in these bimetallic catalysts mainly exist in the form of alloy, and the main role of Au is to reduce the size of AuPt alloy nanoparticles, thus enhancing the adsorption and activation of intermediate products. Through the optimization of various factors (including MgO content, Au/Pt molar ratio, reaction temperature and time), the Au 1 Pt 2 /MgO/SBA-15 (0.05) catalyst exhibits excellent catalytic activity and glyceric acid selectivity for the selective oxidation of glycerol. Density functional theory calculation confirmed that the synergistic effect between Pt and Au active sites could facilitate the oxidation of primary hydroxyl group by promoting the activation of C H bond and the oxidation of aldehyde group. The results may give insights on designing effective Pt based bimetallic catalyst for selective oxidation of glycerol.

Stable and Active Au Catalyst Supported on CeMnO3 Perovskite for Selective Oxidation of Glycerol

“…Noble metal-based catalysts have been widely investigated as effective catalytic materials toward the glycerol oxidation reaction. − However, the noble metal particles easily sinter and agglomerate during the catalytic process as well as the catalyst preparation owing to their Ostwald ripening, which readily loses their surface catalytic active sites. , In order to improve the antisintering ability of noble metal catalysts, a series of optimized strategies have been put forward, including a nanoconfined, support effect and construction of single-atom catalysts. , The support effect refers to utilizing the strong metal–support interaction (SMSI) to enhance the structural stability of the catalyst while inhibiting the agglomeration of nanoparticles to achieve high dispersion. , In order to maximize the SMSI in supported catalysts, the selection of a suitable catalyst support becomes more and more important. − Recently, a series of metal oxides, such as CeO 2 , TiO 2 , and NiO, have been shown as active catalyst supports that can effectively improve the catalytic performance of noble metals. ,, Nevertheless, their stability under harsh reaction conditions toward the glycerol oxidation reaction is still inferior, which can be attributed to their intrinsic structural instability. Compared with the metal oxide, perovskite as the catalyst support has obvious structural advantages.…”

Rational screening of metal catalysts for selective oxidation of glycerol to glyceric acid from microkinetic analysis

“…Through this way of active site regulation, it is highly possible to improve the catalytic activity and glycerol acid selectivity of Pt‐ and Pd‐based catalysts simultaneously. In fact, the previously reported active sites such as PtCo, PtRu, PtCa and PtMg, and so forth have verified this point 13,19,37,44,45 . In addition, Au metal is also a very excellent alternative catalyst because it not only exhibits high glycerol selectivity, but also displays excellent catalyst stability against leaching deactivation in this kind of liquid phase reaction 46,47 .…”

“…Further development of new green process depends on the rational design of high‐performance catalysts. Generally, supported Pt‐, Pd‐ and Au‐based catalysts have been proved to display good catalytic performance for the GLY to GLYA due to their unique d orbital structure 5,12–15 . Unfortunately, the catalytic activity and glyceric acid selectivity of these existing catalysts in this system are not satisfactory due to the limited CH bond activation ability and uncontrollable oxidation side reaction (such as CC bond cleavage) over the active sites 16 .…”

Insight into the selective oxidation mechanism of glycerol to 1,3‐dihydroxyacetoneoverAuCu–ZnOinterface

“…Changed local environment on metal surface atoms suggests the strong electronic coupling effect between Au and Cu atoms (especially on the Au 2 Cu 1 /ZnO catalyst). Therefore, such changes obviously alter the electronic structures of the two metals (Au and Cu) by orbital overlap and electronic coupling, resulting in the higher catalytic activity 51 . UV–vis DR spectra for ZnO‐supported Au and Cu and blank ZnO samples also confirmed the Au‐Cu electronic coupled effect and strong AuCu–ZnO interaction (Figure S4).…”