Ultrafine nanoporous PdFe/Fe3O4 catalysts with doubly enhanced activities towards electro-oxidation of methanol and ethanol in alkaline media

Abstract

Here, we report the fabrication of ultrafine nanoporous PdFe/Fe 3 O 4 electrocatalysts by a facile dealloying strategy. The results show that the phase formation of the as-dealloyed samples is dependent upon the Pd : Fe atomic ratio in the Al-Pd-Fe ternary precursors. The size of ligaments is as small as $2 nm in the nanoporous structure of the as-dealloyed samples, which is the smallest among the literature data reported for nanoporous metals/alloys. The present nanoporous PdFe/Fe 3 O 4 nanocomposites show excellent electrocatalytic activities towards the oxidation of methanol and ethanol in alkaline media due to the double enhancement from Fe 3 O 4 and Fe in PdFe. In addition, the nanoporous PdFe/Fe 3 O 4 sample dealloyed from the Al 75 Pd 12.5 Fe 12.5 precursor exhibits the highest electrocatalytic activity. These materials are potential anode electrocatalysts for applications in direct alcohol fuel cells.

CO oxidation as a test reaction for strong metal–support interaction in nanostructured Pd/FeO powder catalysts

“…One possible state of PdO/Fe 2 O 3 after reduction not considered so far is the formation of Pd-Fe alloys, which can show markedly different catalytic properties compared to non-alloyed Pd [22,23]. Bulk sensitive XRD has been applied on the 5% catalyst to check for alloy formation at HTR.…”

Sponge-like carbon thin films: The dealloying concept applied to copper/carbon nanocomposite

“…The high specific surface area of this kind of material confers them exceptional properties such as super-hydrophobicity [1,2], enhanced catalysis activity [3][4][5][6], and very selective filtering ability [7,8]. Various materials were used to synthesize nanoporous structures including metals (e.g., Au [6,[9][10][11][12][13][14], Pt [15][16][17][18], and Ag [19,20]), oxides (e.g., TiO 2 [21][22][23] and SiO 2 [24,25]) and carbon [26][27][28][29][30][31][32][33][34][35][36].…”

“…In general, the material forming the skeleton of the nanoporous structure is selected according to the aimed application. For example, electrically insulating nanoporous materials are most of the time studied for self-cleaning or filtration applications [26,37], whereas the conductive ones are preferred as electrodes for supercapacitors [15,33,34,36,[38][39][40][41][42] and hydrogen storage devices [43,44], or as catalysts [3][4][5]22,24,27,45].…”

Electrocatalytic performance for methanol oxidation on nanoporous Pd/NiO composites prepared by one-step dealloying

“…At present, lots of investigations have been focused upon Pt and Pt-based materials which are believed to be the best catalysts for low temperature fuel cells http://dx.doi.org/10.1016/j.fuel.2016.04.086 0016-2361/Ó 2016 Elsevier Ltd. All rights reserved. [2][3][4][5]. However, the commercialization of Pt and Pt-based catalysts in fuel cells is severely restricted by their high cost, sluggish kinetics, poor stability, low utilization and weak methanol-tolerant capacity [6,7].…”