Facile Green Synthesis of Nanorod-Built AuPt Flowers in Deep Eutectic Solvents and Their Highly Selective Hydrogenation of Cinnamaldehyde
Tianhang Liu, Kaisheng Yao, Xiangyan Zhang, Shijie Li, Weiwei Lu, Chenchen Zhao, Yingxiong Wang
Abstract
High Resolution Image Download MS PowerPoint Slide The anisotropic bimetal nanoflowers have demonstrated exceptional performance across various fields and gained significant attention, but their green one-pot preparation still remains a technical challenge. Here, a pioneering effort is represented for the synthesis of nanorod-built AuPt nanoflowers (NFs) in a deep eutectic solvent (DES) composed of choline chloride (ChCl) and urea with H 2 PtCl 6 and HAuCl 4 as metal precursors and ascorbic acid as the reducing agent, demonstrating the environmentally friendly, sustainable, and facile characteristics. The ingenious strategy involves the addition of water to modulate the solvent environment of DES for the optimal growth of AuPt NFs. The results of nuclear magnetic resonance elucidate the water–DES interactions and interestingly reveal that a similar solvent environment within the water content range of 14.1–19.8 wt % is found, in which the well-defined AuPt NFs can be grown. Benefiting from the unique 3D self-supported flower-like structures and electronic synergistic effect of AuPt NFs-1catalyst, 98.5% cinnamaldehyde (CAL) can be converted, and the selectivity toward hydrocinnamaldehyde (HCAL) is as high as 93.2% after 6.0 h of the reaction at 60 °C under 1.0 H 2 MPa. After 5 cycles, AuPt NFs-1 still maintains good catalytic performance achieving 97.3% CAL conversion and 90.1% HCAL selectivity. The innovative and eco-friendly synthesis strategy of producing 3D AuPt NFs will provide new insights into metal nanocatalysts for catalytic hydrogenation of CAL to HCAL, as well as various other applications.