Promotion of PdCu/C Catalysts for Ethanol Oxidation in Alkaline Solution by SnO₂ Modifier

Abstract

The development of high performance PdCu/C catalysts through manipulation of reduction temperatures and addition of SnO2 promoter has been elucidated systematically in order to enhance ethanol oxidation reaction (EOR) performance. The structure, morphology, surface species, and electroactivity of the PdCu/C and SnO2‐modified PdCu/C catalysts are characterized by use of X‐ray diffraction, high resolution transmission electron microscopy, X‐ray photoelectron spectroscopy, and cyclic voltammetry. For the PdCu/C catalysts, the ratio of the forward anodic peak current density to that of the reverse, that is, the If/Ib ratio, the degree of alloying (Dalloy), grain size, and EOR performance increases as the reduction temperature increases to 570 K. However, severe sintering at 670 K deteriorates EOR performance. Therefore, 570 K is a suitable reduction temperature for the preparation of PdCu/C catalysts with fine alloy structure, small crystal size, good Dalloy, good anti‐poisoning ability, and excellent EOR performance. For the SnO2 modified PdCu/C catalysts, addition of 20 wt % Sn may cause a large amount of SnO2 to form on the surface and block the active site of the catalysts, thus decreasing EOR performance. However, addition of 10 wt % Sn promotes stability in EOR performance, attributable to the significant amount of PdSn phase in the bulk and SnO2 species on the surface, which enhance the CO oxidation ability and electrochemical surface area. Consequently, based on the chronoamperometric measurements after 1 hr, the EOR activity of PdCu/C catalysts with 10 wt % SnO2 modification is enhanced by approximately 230 % compared with the as‐reduced sample.

Synthesis and Gas Sensing Properties of Single La-Doped SnO2 Nanobelts

“…However, tin oxide has problems related to its poor selectivity towards various gases. In general, suitable catalysts, noble metals, and transition metals are inserted into SnO 2 sensors to improve their selectivity and sensing response [ 6 , 7 , 8 ]. These metals’ catalytic activities, coupled with the semiconductor properties of the materials used, have resulted in their applications for detection of organic, inorganic vapors, and other toxic, inflammable or hazardous gases [ 9 , 10 ].…”

Tin as a co-catalyst for electrocatalytic oxidation and reduction reactions

“…172 However, the addition of excess Sn may lead to the formation of a large amount of SnO 2 on the catalyst surface, blocking the active sites of the catalyst and thus reducing the EOR performance. 173 As to the HER, adding Sn into MoS 2 has a twofold effect. Sn, as a type II co-catalyst, can create additional active sites in MoS 2 .…”

Ga-Doped 3D Ordered Porous SnO2 for Enhanced Formaldehyde Sensing Performance

“…The porosity and orderliness significantly improved the specific surface area, electron transport capabilities, and active site density of SnO 2 nanomaterials. In addition, suitable noble metals and transition metals are inserted into SnO 2 sensors; these metals’ activities coupled with the semiconductor properties could improve their selectivity and sensing response. − …”