Spectroelectrochemical Study of Carbon Monoxide and Ethanol Oxidation on Pt/C, PtSn(3:1)/C and PtSn(1:1)/C Catalysts.
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.
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. rjrizo57@gmail.com.
Rubén
R
Rizo
Instituto de Carboquímica (CSIC) Miguel Luesma Castan 4, Zaragoza 50018, Spain. mlazaro@icb.csic.es.
María Jesús
MJ
Lázaro
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. epastor@ull.edu.es.
Elena
E
Pastor
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. ggarcia@ull.edu.es.
Gonzalo
G
García
D002248:Carbon Monoxide / Q000737:chemistry*; D002384:Catalysis; D055664:Electrochemical Techniques; D000431:Ethanol / Q000737:chemistry*; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D014001:Tin / Q000737:chemistry*
D000431:Ethanol; D010984:Platinum; D014001:Tin; D002248:Carbon Monoxide
DEMS; FTIRS; Pt-Sn electrocatalysts; direct ethanol fuel cell; ethanol electrooxidation