Yufen Wang,Yantao Wang,Yongqing Ma,Asma Mohmmad Elsharif,Chen Zhang,Weiran Yang,Christophe Len
A new transition-metal-free catalytic system which uses sodium iodide as the catalyst with formic acid as the hydrogen donor in a biphasic medium was reported for the reduction of the hydroxyl group and various unsaturated groups such as CC, CC, CN and CO. Using the same catalytic system, reductive N-formylation of nitroarenes with formic acid was explored to produce the corresponding amide in high selectivity. Moreover, the catalyst stability was evaluated and reaction mechanisms were studied and proposed for the three model reactions.
Kai Wang,Rinrada Sriphathoorat,Shuiping Luo,Min Tang,Hongyu Du,Pei Kang Shen
We first report an effective high-yield (∼100%) synthesis of ultrathin PtCu hexapod nanocrystals. The obtained nanocrystals have three-dimensional (3D) accessible surfaces, and the pod diameter is as thin as only 3.57 nm while the pod length ranges up to 15.28 nm. Moreover, the length and diameter of the pods can be well controlled by simply tuning the amount of NaI added into the system. The formation mechanism is investigated based on the experimental observations, indicating that iodide ions play a critical role in forming the ultrathin PtCu hexapod nanocrystals. Due to their highly open structure and ultrathin pods, the as-prepared ultrathin PtCu hexapod nanocrystals have relatively large surface areas as well as abundant tips and thus exhibit enhanced catalytic activity in the electro-oxidation of methanol and ethanol in comparison with commercial Pt/C, state-of-the-art Pt-based nanodendrites, and PtCu nanoalloy catalysts.