Aqueous-phase aerobic oxidation of alcohols by soluble Pt nanoclusters in the absence of base

Abstract

A soluble Pt nanocluster catalyst (Pt-GLY) is efficient in the absence of base for aqueous-phase aerobic oxidation of, in particular, non-activated alcohols with high recyclability.

High-yield synthesis of PVP-stabilized small Pt clusters by microfluidic method

“…8 shows the time course of the conversion of PhCH 2 OH in the presence of sample a at 60 °C. Interestingly, this reaction afforded PhCHO as the major product, in sharp contrast to the selective production of PhCO 2 H catalyzed by the PtNPs reported previously [2,3,5,6]. The yield of PhCHO became as high as 84% after 4 h. The high selectivity of sample a to the aldehyde product can be ascribed to several factors, such as size, geometric and electronic structures of the PtNPs, which would be investigated in a future study.…”

“…Recently, much attention has been paid on their catalytic application from the viewpoint of reduction of environmental impact and conservation of precious resource [1]. One of the most extensively studied reactions is the aerobic oxidation of alcohols in water in the presence of Pt nanoparticles (PtNPs) as catalysts [2][3][4][5][6]. Since the ubiquitous oxygen is used as the oxidant instead of stoichiometric amounts of heavy-metal oxidants such as CrO 3 and KMnO 4 , production of harmful byproducts are suppressed in the reaction [7,8].…”

“…One of the most extensively studied reactions is the aerobic oxidation of alcohols in water in the presence of Pt nanoparticles (PtNPs) as catalysts [2][3][4][5][6]. Since the ubiquitous oxygen is used as the oxidant instead of stoichiometric amounts of heavy-metal oxidants such as CrO 3 and KMnO 4 , production of harmful byproducts are suppressed in the reaction [7,8]. Efficient production of small monodisperse PtNPs is desirable for the following reasons: (1) the amount of Pt, a precious metal, can be minimized by increasing the surface-to-volume ratio of the NPs; (2) the catalytic activity per unit surface area increases with a decrease in NP size as suggested by Liu [6].…”

“…In general, PtNPs are prepared via the chemical reduction of Pt 4+ ions by hydrogen [6,9], alcohols [2,5,[10][11][12][13], borohydride [14][15][16][17][18], glycol [3,6], or ethylene glycol [19,20] in the presence of a stabilizer or on a solid support (Scheme 1). Among the aforementioned reducing agents, borohydride (BH 4 -) is most suitable for minimizing the particle size because it enables rapid reduction to afford very small nuclei, whose growth is hindered.…”

Influence of crystal size of HZSM-5 on hydrodeoxygenation of eugenol in aqueous phase

“…For the selective hydrogenation or oxidation of some bio-derived compounds, water is reported as a good reaction medium under moderate conditions [6][7][8], and a series of catalysts which combined of Pd/C and HZSM-5 have been developed for aqueous-phase hydrodeoxygenation of phenolic oil, such as Pd/C and liquid acid, base metal Raney Ni and solid acid [5,9,10]. Besides, Pd/HZSM-5 and Ni/HZSM-5 catalysts are also prepared for one-pot aqueous-phase upgrading of the organic components in crude bio-oil [3,11].…”