Synergistic effect of Ni^(Ⅱ)and Co/Fe^(Ⅲ)in doped mixed-valence phosphonate for enhancing electrocatalytic oxygen evolution

Metal organophosphonates have been explored in energy-related fields due to their high chemical and thermal stability as a type of uniformly precursor,but only few of pristine metal organophosphonate are directly used for oxygen evolution reaction(OER)catalysts.Here,a mixedvalence iron phosphonate(Fe_(3)-ppat)has been constructed and applied to OER catalysis considered the potential active sites in pillars Fe^(Ⅱ)(-H_(2)O)_(4)(COO)_(2)and inorganic layers Fe^(Ⅲ)(μ_(2)–OH)PO_(3).Specifically,isostructural trimetallic framework Fe_(1.7)Co_(0.3)Ni_(1.0)-ppat possesses a minimum overpotential(291 mV),small Tafel slope(91.65 mV dec^(-1)),and high stability up to 83 h.The enhanced catalytic performance could be mainly ascribed to the synergistic effect of Ni^(Ⅱ)equivalent occupancy in pillars and Co/Fe^(Ⅲ)in layers.

A high dispersed Pt_(0.35)Pd_(0.35)Co_(0.30)/C as superior catalyst for methanol and formic acid electro-oxidation

Pt：Pd：Co ternary alloy nanoparticles were synthesized by sodium borohydride reduction under nitrogen, and were supported on carbon black as catalysts for methanol and formic acid electro-oxidation. Compared with Pt0.65C00.35/C, Pt/C, Pd0.65C00.35/C, and Pd/C catalyst, Pt0.35Pd0.35Co0.30/C exhibited relatively high durability and strong poisoning resistance, and the Pt-mass activity was 3.6 times higher than that of Pt/C in methanol oxidation reaction. Meanwhile, the Pt0.35Pd0.35Co0.30/C exhibited excellent activity with higher current density and higher CO tolerance than that of Pt0.6sCo0.35/C, Pt/C, Pd0.65C00.35/ C, and Pd/C in formic acid electro-oxidation.

Fe_(2)Mn(μ_(3)-O)(COO)_(6) Cluster Based Stable MOF for Oxidative Coupling of Amines via Heterometallic Synergy

The direct catalytic oxidative coupling of amines is one of the attracting methods for the synthesis of a variety of pharmaceutical or industrial needed imines.Numerous earth-abundant manganese based salts,oxides,and complexes have been applied in this reaction.However,these compounds suffered from difficult separation,large catalyst loading,complicated reactivation or indeterminate activity.Considering the facts that metal-organic frameworks(MOFs)with crystalline structure,precise composition,and enormous surface area have superior performance in heterogeneous catalytic reactions,herein,we introduced Mn into[Fe_(3)(μ_(3)-O)(CH_(3)COO)_(6)],one of the precursors for the preparation of stable MOFs,and got[Fe_(2)Mn(μ_(3)-O)(CH_(3)COO)_(6)]cluster.After ligand replacement with biphenyl-3,4’,5-tricarboxylic acid(BPTC),heterometallic cluster-based[Fe_(2)Mn(μ_(3)-O)(BPTC)2(DMF)2(H_(2)O)](1)was obtained.As expected,1 is stable and able to catalyze the homo-or cross-coupling of amines effectively and selectively with 0.9 mol%catalyst loading at room temperature.Control experiments indicated that the catalytic activity of 1 mainly stems from Mn sites and that Fe synergistically contributes to the stability.Additionally,1 is recyclable and can be reused easily for at least 8 runs without obvious decrease in catalytic ability.To our knowledge,1 should be the first heterometallic cluster-based MOF with defined structure suitable for the synthesis of diverse imines from oxidative coupling of amines under mild conditions,which may shed light on the easy preparation of effective heterogeneous catalysts for organic synthesis.

Concave Pt-Cu-Fe ternary nanocubes：One-pot synthesis and their electrocatalytic activity of methanol and formic acid oxidation

Concave nanostructures may be developed to improve the specific mass activity of a catalyst for formic acid and methanol electro-oxidation. In this work, we report the elctrocatalytic oxidation of methanol and formic acid in acid medium over concave Pt-Cu-Fe ternary nanocubes（NCs）, obtained by the galvanic exchange of Pt and Fe on Cu NCs. The concave Pt-Cu-Fe NCs exhibited improved electrooxidation performance contrasted to Pt-Cu NCs and purchased commercial Pt/C as demonstrated by their improved durability, lower onset potential, and more preferable anti-poisoning properties. These properties are believed to originate from the tailored concave structure of the catalyst and possible synergetic effects among the components of the Pt-Cu-Fe NCs.