Promotion of Ternary Pt–Sn–Ag Catalysts toward Ethanol Oxidation Reaction: Revealing Electronic and Structural Effects of Additive Metals

Abstract

The use of a computation-guided method and the discovered structure–property relationship would establish a rational strategy to aid the development of ethanol oxidation reaction (EOR) catalysts for possible commercialization of direct ethanol fuel cells. Here, we investigate the promotion roles of additive metals in ternary Pt–Sn–Ag catalysts toward EOR via a combination of density functional theory calculation and experimental evidence. By calculating the EOR energetics, the promotion roles of Sn and Ag were revealed from the viewpoints of electronic and structural effects, respectively: (1) The addition of Sn and Ag on Pt essentially reduce the reaction energy and activation barrier of the second two-electron transfer process of EOR, facilitating the oxidation of acetaldehyde to acetic acid; (2) a homogeneous Pt–Sn–Ag surface configuration strengthens the adsorption energy of ethanol, thus improving the activity for ethanol oxidizing to acetaldehyde. Experimentally, various Pt–Sn–Ag nanorod catalysts with different surface configurations were synthesized, and their electrochemical performances demonstrate the two EOR promotion effects as predicted. Notably, our extended Pt6–Sn–Ag nanorod catalyst shows remarkably enhanced EOR activity and stability, highlighting a homogeneous Pt–Sn–Ag surface configuration as an optimal structure for EOR catalysts.

In Situ TEM Studies of Catalysts Using Windowed Gas Cells

“…EDS was used to confirmed the chemical composition [53,[84][85][86], while EELS was applied to confirm the surface elemental composition in different faces [84].…”

Controllable synthesis of platinum–tin intermetallic nanoparticles with high electrocatalytic performance for ethanol oxidation

“…are regarded as the most prominent nanoelectrocatalysts for the EOR or methanol oxidation reaction (MOR). [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] For example, CO, CO 2 , and acetic acid (CH 3 COOH) could be observed at lower potentials, which indicates that the Pt 3 Sn alloy, in contrast with commercial Pt/C, has a negative onset potential shift of 100 mV for the EOR. 3,24 This is due to its higher ability to cleave the C-C bond at low overpotentials and reduced binding energy for CO so as to avoid its poison.…”

Highly Safe, Durable, Adaptable, and Flexible Fuel Cell Using Gel/Sponge Composite Material

“…[ 22,25 ] For fuel cells, the catastrophic effect could be caused by fuel leakage, which is induced by mechanical abusive loading. [ 41,42 ] Because current fuel cells usually use high energy density fuels, such as hydrogen, [ 43 ] methanol, [ 44–53 ] ethanol, [ 54–58 ] etc., the leakage of these fuels can easily cause serious safety problems, such as asphyxia, toxicity, fire, or even explosions (Scheme 1). Currently, most of the attention is focused on the early warning of fuel leakage, [ 41,42 ] but more attention should be paid to problem‐solving.…”