Surface engineering improving selective hydrogenation of p-chloronitrobenzene over AuPt alloy/SnNb2O6 ultrathin nanosheets under visible light

• Published in: Chemical engineering science 2022-11, Vol.262, p.117936, Article 117936
• Main Authors: Wang, Zhiwen, Wang, Huan, Shi, Yingzhang, Liu, Cheng, Wu, Ling, Liang, Shijing
• Format: Article
• Language: English
• Subjects: AuPt alloy; Halonitrobenzenes; Lewis Base sites; Photocatalytic hydrogenation; SnNb2O6 nanosheets
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2022.117936

Surface Engineering Improving Selective Hydrogenation of p-Chloronitrobenzene over AuPt alloy/SnNb2O6 ultrathin nanosheets under Visible light. [Display omitted] •Bimetallic alloy AuPt decorated SnNb2O6 nanosheet (AuPt/SN) as a photocatalyst has been constructed successfully.•The catalyst (Au0.5Pt0.5/SN) exhibits a high catalytic conversion efficiency for p-chloronitrobenzene (99.8%) with a selectivity of p-chloroaniline (99.1%).•SN could activate p-chloronitrobenzene via a Sn2+···–NO2 coordination.•A synergetic effect among Lewis base sites (Sn2+), AuPt alloy and photogenerated electrons is proposed.•A photocatalytic mechanism is determined at molecule scale. AuPt alloy/SnNb2O6 ultrathin nanosheet (AuPt/SN) as a photocatalyst is constructed for selective hydrogenation of p-chloronitrobenzene (p-CNB) under visible light irradiation. A typical catalyst (Au0.5Pt0.5/SN) exhibits a high conversion of halonitrobenzenes (99.8%) and selectivity of haloaniline (99.1%). The results of in situ ATR-IR, XPS and Raman indicate a preferential chemoselective adsorption of –NO2 that Lewis base sites (Sn2+) on the catalyst could selectively coordinate with –NO2 whereas C-Cl bond is not be bonded, improving the catalytic selectivity. Atom Pt in alloy is responsible for the formation of ·H, while Au inhabits the dissociation of C-Cl via repressing the generation of Pt-H. The photogenerated electrons can accelerate the ·H formation. ·H could be transferred to Sn2+ sites for the hydrogenation of –NO2 by hydrogen spillover. Therefore, the high performance of the catalyst can be attributed to a surface synergetic effect among Lewis base sites (Sn2+), AuPt alloy and photogenerated electrons.