Controllable Synthesis of PtIrCu Ternary Alloy Ultrathin Nanowires for Enhanced Ethanol Electrooxidation

Abstract

Rational design and controllable synthesis of catalysts with unique structure and composition are effective ways to promote electrocatalytic ethanol oxidation, thus contributing the direct ethanol fuel cells to gain ground. Herein, 2.5 nm-thin PtIrCu ternary alloy ultrathin nanowires (UNWs) with high-density planar defects are synthesized via oriented attachment with the assistance of H 2 . By adjusting the contents of Ir and Cu atoms, we find that the structure of the products changed from nanowires (NWs) to nanoparticles with the increase of Ir content. Density functional theory calculations show that when Cu atoms are replaced by Ir atoms, the vacancy formation energy of Pt atoms is increased, making the Pt atoms difficult to be activated by H 2 , which is not conducive to the formation of a one-dimensional structure. The optimal Pt 43 Ir 32 Cu 25 UNWs achieve excellent ethanol electrooxidation reaction activity (1.05 A•mg −1 Pt and 1.67 mA•cm −2 ), for it can significantly reduce the onset potential and improve the ability of CO anti-poisoning. The significant improvement in catalytic performance is attributed to the synergistic effect of the alloy and the NW structure with high-density planar defects.

Milestones of Electrocatalyst Development for Direct Alcohol Fuel Cells

“…The addition of third metals into bimetallic Pt-based catalysts to form a ternary one is an effective approach to reduce Pt utilization and improve catalytic performance. [62,72] In this case of the binary PtSn-M alloy, Jacob et al [73] fabricated ternary PtSn-Ce catalysts with different atomic ratios through a modified formic acid method using different precursors (H 2 PtCl 6 .6H 2 O, CeCl 3 , and SnCl 2 ). Ternary PtSn-Ce electrocatalysts demonstrated catalytic activity and CO-tolerant ability greater than PtCe/C and Pt/C catalysts.…”

Ultrathin Pt3Pb nanowires prepared in the aqueous phase for enhanced methanol electrooxidation

“…25,26 H 2 is a strong reducing agent and can reduce many kinds of metal ions including but not limited to Fe 3+ , Ni 2+ , Co 2+ , Cu 2+ , Ru 3+ , Ir 3+ etc. 27,28 In our synthesis method, H 2 PtCl 6 and (CH 3 COO) 2 Pb are co-reduced by in situ H 2 , coming from DMF and H 2 O, to form alloy nanoparticles. Next, H atoms adsorbed on the surface of the nanoparticles can induce the nanoparticles to merge with each other to form 1D NW structures, as shown in Fig.…”

Phosphorus-Doped PdSn Nanocatalyst with Abundant Defective Atoms for Enhanced Methanol Oxidation

“…The excessive use of traditional fossil fuels has brought a lot of environmental problems to mankind, so it is urgent to seek clean energy storage and conversion technology to solve the pollution problem. − Fuel cells have received a lot of attention from scientists because they emit only water. − Among them, direct methanol fuel cells have attracted much attention because of their convenient synthesis and transportation of raw materials. , Palladium is the most promising candidate to catalyze the electrocatalytic oxidation of methanol in direct methanol fuel cells. − However, palladium is a rare metal, and its high price and rare reserves strictly limit its large-scale use in fuel cells . Therefore, it is very important to design and synthesize efficient Pd-based electrocatalysts for methanol oxidation to reduce the dosage of palladium atoms.…”