In situ high-potential-driven surface restructuring of ternary AgPd–Pt_dilute aerogels with record-high performance improvement for formate oxidation electrocatalysis

Abstract

The in situ high-potential-driven restructuring of ternary AgPd–Ptdilute aerogels exhibits unprecedented activity improvement for formate electrooxidation.

Benchmarking Catalysts for Formic Acid/Formate Electrooxidation

“…Another alloy based on PdCu consists of an aerogel synthesized sol-gel method and supercritical drying, which achieved a maximum current de mA cm −2 [129]. It is noteworthy that in the previously mentioned work with Pd a nanoparticles, Chen et al also explored the use of PdCuPt trimetallic alloy and t lyst has a similar onset potential as PdCu, 0.5 V vs. RHE, but the highest curren There is a plethora of publications using alloys based on Pd, the full scope of which is beyond this review [71,73,115,118,120,122,[124][125][126]128,129,133,134]. However, in a few exemplary studies, the maximum current, onset potential, propensity towards poisoning and stability can be improved when alloying Pd with metals such as Bi [124], Sn [135], Cd [124], In [125], Ag [71,115,118,[126][127][128], Cu [32,128,129,134], Ce [118], Co [118,133], Ni [118,120,126], Pt [39,71,73,91,92] and Au [129] (Table 3).…”

“…While Pd has been used as a pure materia in inks, its loading can be decreased, and its amount thus reduced (thereby decreasing costs). Similar to the strategies followed with Pt-based catalysts, the primary way that Pd loading is decreased is by mixing it with an electrically conducting substrate such as Vul can carbon (carbon black) [53,70,[115][116][117][118][119][120][121], graphene [121], carbon nanotubes [121], re Similar to the strategies followed with Pt-based catalysts, the primary way that Pd loading is decreased is by mixing it with an electrically conducting substrate such as Vulcan carbon (carbon black) [53,70,[115][116][117][118][119][120][121], graphene [121], carbon nanotubes [121], reduced graphene oxide [117,122] and TiO 2 nanotubes [73]. The results of those studies show a strong correlation between catalyst loading, the support material and the precise solution conditions with maximum current densities ranging from 0.6 mA cm −2 to 140 mA cm −2 .…”

“…In principle, the energy of adsorbed species can be controlled by factors such as, for example, pr ergy levels, symmetry or atomic spacing, all of which can be tuned through the s of alloys of Pd. There is a plethora of publications using alloys based on Pd, the full scope is beyond this review [71,73,115,118,120,122,[124][125][126]128,129,133,134]. However, exemplary studies, the maximum current, onset potential, propensity towards p and stability can be improved when alloying Pd with metals such as Bi [124], Sn [124], In [125], Ag [71,115,118,[126][127][128], Cu [32,128,129,134], Ce [118], Co [118 [118,120,126], Pt [39,71,73,91,92] and Au [129] (Table 3).…”

“…Similar to the strategies followed with Pt–based catalysts, the primary way that Pd loading is decreased is by mixing it with an electrically conducting substrate such as Vulcan carbon (carbon black) [ 53 , 70 , 115 , 116 , 117 , 118 , 119 , 120 , 121 ], graphene [ 121 ], carbon nanotubes [ 121 ], reduced graphene oxide [ 117 , 122 ] and TiO 2 nanotubes [ 73 ]. The results of those studies show a strong correlation between catalyst loading, the support material and the precise solution conditions with maximum current densities ranging from 0.6 mA cm −2 to 140 mA cm −2 .…”

“…In order to decrease the observed poisoning of FA electrooxidation catalysts based on Pd, many authors have examined a variety of techniques, ranging from Pd–H [ 123 ], Pd monolayers on other metals [ 74 ], nanoparticle alloys [ 71 , 73 , 118 , 120 , 122 , 124 , 125 , 126 , 133 , 134 ], core shells [ 126 ], nanotubular alloys [ 127 ] and aerogel alloys [ 115 , 128 , 129 ]. Interestingly, it was shown that the poisoning effects for Pd-H was greatly reduced when compared with native Pd and the authors attribute this change in reactivity to hydrogen-mediated reduction of adsorbed CO to formaldehyde, which is then oxidized to carbonate ( Figure 9 ) [ 123 ].…”