Active and Recyclable Gold Metal Nanoparticles Catalyst Supported on Nitrogen‐Doped Mesoporous Carbon for Chemoselective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol

Abstract

Several supported gold metal catalysts with different Au nanoparticles sizes were prepared and evaluated for the chemoselective hydrogenation of cinnamaldehyde (CA) to cinnamyl alcohol (CAL). To investigate the structure‐activity relationship, stability of catalyst, heterogeneity and recyclability, the structural characteristics of materials and Au catalysts (fresh and spent catalysts) were studied by employing variety of physico‐chemical techniques. The interrelationship among Au nanoparticles size (nm) with turnover frequency (h−1) of Au catalysts has also been explored. Among the various Au catalysts tested, nitrogen‐doped mesoporous carbon (NMC) supported Au catalyst having homogeneously dispersed (78.8%) Au nanoparticles (1.6 nm) synthesized by sol‐immobilization method (Au‐NMC‐SI) demonstrated improved catalytic activity affording 78% CAL selectivity and 94.2% CA conversion without using any promoter. Moreover, Au‐NMC‐SI catalyst exhibited good recyclability and stability. The catalyst synthesis approach described in this investigation opens up a novel strategy for the design of highly efficient metal nano‐catalysts supported on NMC materials.

Sustainable aviation fuel from prehydrolysis liquors

“…Later, this catalyst was tested for the hydrogenation of various aldehydes to alcohols, showing high selectivity. 14 A similar mechanism was also proposed by Nagpure et al, 31 for hydrogenation of cinnamaldehyde, based on the heterolytic dissociation of H 2 , followed by the transfer of nucleophilic H − ion to electrophilic carbonyl carbon of the aldehyde, whereas the electrophilic H + ion transfers to nucleophilic carbonyl oxygen, leading to the desired alcohol. Gratifyingly, the Au@NC/TiO 2 catalyst showed very high selectivity in the conversion of furfural to furfuryl alcohol, reaching full conversion and no other side-products (Table 1, entry 4).…”

Schiff Base Functionalized Cellulose: Towards Strong Support-Cobalt Nanoparticles Interactions for High Catalytic Performances

“…According to the mechanism suggested [93] to reach high COL selectivity, the size of the particles remains constant with a low or no sintering process occurring. According to the literature [97], the hydrogenation of cinnamaldehyde using cobalt particles as a catalyst involves the reduction of the aldehyde functional group (-CHO) to the corresponding alcohol (-CH 2 OH) using molecular hydrogen (H 2 ). Cobalt supported on modified dialdehyde cellulose acts as a catalyst to facilitate this reaction.…”

“…The presence of basic nitrogen species in the vicinity of Co nanoparticles may facilitate the heterolytic cleavage of molecular H 2 , dissociating into hydride H − and proton H + . Consequently, the proton will be located at the basic nitrogen site and the hydride will be located at the Co nanoparticle site [97,99,100]. Next, the nucleophilic hydride migrates from the cobalt surface to the electrophilic carbonyl carbon of the adsorbed cinnamaldehyde molecule, resulting in the formation of an adsorbed alkoxide intermediate, which undergoes further hydrogenation by accepting additional electrophilic H + ion moves from the surface to the nucleophilic carbonyl oxygen leads to the formation of the desired product.…”

Facile Hydrogenation of Furfural by MOF‐Derived Graphitic Carbon Wrapped FeCo Bimetallic Catalysts

“…Hence, the judicious choice of a surfaceprotecting agent is essential. [34,35] A mesoporous carbon sheet, in this respect, has the advantage of high thermal stability and easy regeneration for catalyst recycling. In this study, based on the knowledge of their electronic structure obtained in earlier studies, [19,[36][37][38] bimetallic FeCo catalysts were wrapped in graphitic carbon to develop catalysts that are easily controllable, robust, magnetically recoverable, and have readily accessible sites.…”

“…Some surface agents even enhance the selectivity of important chemical processes by influencing the adsorption geometries of substrates on the surface of catalysts. Hence, the judicious choice of a surface‐protecting agent is essential [34,35] . A mesoporous carbon sheet, in this respect, has the advantage of high thermal stability and easy regeneration for catalyst recycling.…”