Rizo Rubén, Lázaro María Jesús, Pastor Elena, García Gonzalo
Departamento de Química, Instituto de Materiales y Nanotecnología, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, La Laguna 38071, Santa Cruz de Tenerife, Spain.
Instituto de Carboquímica (CSIC) Miguel Luesma Castan 4, Zaragoza 50018, Spain.
Molecules. 2016 Sep 12;21(9):1225. doi: 10.3390/molecules21091225.
PtSn-based catalysts are one of the most active materials toward that contribute ethanol oxidation reaction (EOR). In order to gain a better understanding of the Sn influence on the carbon monoxide (principal catalyst poison) and ethanol oxidation reactions in acidic media, a systematic spectroelectrochemical study was carried out. With this end, carbon-supported PtSnx (x = 0, 1/3 and 1) materials were synthesized and employed as anodic catalysts for both reactions. In situ Fourier transform infrared spectroscopy (FTIRS) and differential electrochemical mass spectrometry (DEMS) indicate that Sn diminishes the amount of bridge bonded CO (COB) and greatly improves the CO tolerance of Pt-based catalysts. Regarding the effect of Sn loading on the EOR, it enhances the catalytic activity and decreases the onset potential. FTIRS and DEMS analysis indicate that the C-C bond scission occurs at low overpotentials and at the same potential values regardless of the Sn loading, although the amount of C-C bond breaking decreases with the rise of Sn in the catalytic material. Therefore, the elevated catalytic activity toward the EOR at PtSn-based electrodes is mainly associated with the improved CO tolerance and the incomplete oxidation of ethanol to form acetic acid and acetaldehyde species, causing the formation of a higher amount of both C2 products with the rise of Sn loading.
基于PtSn的催化剂是对乙醇氧化反应（EOR）最具活性的材料之一。为了更好地理解锡对酸性介质中一氧化碳（主要催化剂毒物）和乙醇氧化反应的影响，开展了一项系统的光谱电化学研究。为此，合成了碳载PtSnx（x = 0、1/3和1）材料，并将其用作这两种反应的阳极催化剂。原位傅里叶变换红外光谱（FTIRS）和差分电化学质谱（DEMS）表明，锡减少了桥式键合CO（COB）的量，并大大提高了铂基催化剂的CO耐受性。关于锡负载量对EOR的影响，它提高了催化活性并降低了起始电位。FTIRS和DEMS分析表明，无论锡负载量如何，C-C键的断裂都在低过电位和相同电位值下发生，尽管随着催化材料中锡含量的增加，C-C键的断裂量会减少。因此，基于PtSn的电极对EOR的催化活性提高主要与CO耐受性的改善以及乙醇不完全氧化形成乙酸和乙醛物种有关，随着锡负载量的增加，这两种C2产物的生成量会增加。
