Synergistic Effect of Segregated Pd and Au Nanoparticles on Semiconducting SiC for Efficient Photocatalytic Hydrogenation of Nitroarenes

Abstract

Efficient catalytic hydrogenation of nitroarenes to anilines with molecular hydrogen at room temperature is still a challenge. In this study, this transformation was achieved by using a photocatalyst of SiC-supported segregated Pd and Au nanoparticles. Under visible-light irradiation, the nitrobenzene hydrogenation reached a turnover frequency as high as 1715 h at 25 °C and 0.1 MPa of H pressure. This exceptional catalytic activity is attributed to a synergistic effect of Pd and Au nanoparticles on the semiconducting SiC, which is different from the known electronic or ensemble effects in Pd-Au catalysts. This kind of synergism originates from the plasmonic electron injection of Au and the Mott-Schottky contact at the interface between Pd and SiC. This three-component system changes the electronic structures of the SiC surface and produces more active sites to accommodate the active hydrogen that spills over from the surface of Pd. These active hydrogen species have weaker interactions with the SiC surface and thus are more mobile than on an inert support, resulting in an ease in reacting with the N═O bonds in nitrobenzene absorbed on SiC to produce aniline.

Magnetically Hollow Pt Nanocages with Ultrathin Walls as a Highly Integrated Nanoreactor for Catalytic Transfer Hydrogenation Reaction

“…Due to the limited availability of natural products, the large amount demand of the dyestuffs, pharmaceutical, agricultural chemicals, and polymers for aromatic amines was satisfied by the catalytic transfer hydrogenation of their corresponding nitroarenes . It was reported that the requirement of anilines compounds is more than 4 million tons per year and the value of these chemical intermediates will increase to £10.17 billion by 2020 . Many previous works have reported about this transformation over noble metal and noble metal‐free catalyst.…”

Silicon Carbide Supported Palladium‐Iridium Bimetallic Catalysts for Efficient Selective Hydrogenation of Cinnamaldehyde

“…Recently, high specific surface area β‐SiC has been supposed as a potential support alternatives to carbon materials due to its stable chemical property, high mechanical strength and good thermal conductivity . In the previous researches, we found that the electron transfer occurred between metals and SiC caused by Mott‐Schottky effect, which can significantly tune the activity and selectivity of SiC‐supported metallic catalysts …”

Progress in the Utilization Efficiency Improvement of Hot Carriers in Plasmon-Mediated Heterostructure Photocatalysis

“…In PMH, the recombination of electron-hole pairs cannot be thoroughly avoided due to short pathways for transferring charges and due to the relatively high interfacial potential barrier. The rational design of the potential gradient between plasmonic metals and the semiconductor is an efficient way for reducing potential differences and inducing the controllable transporting of HCs [101][102][103][104]. Based on this, Chen et al [101] reported TiO 2 nanotube-Al 2 O 3 -Au ternary structures for the efficient separation of HCs excited by Au nanospheres (Figure 9a).…”