Monodispersed ultrathin twisty PdBi alloys nanowires assemblies with tensile strain enhance C_(2+)alcohols electrooxidation

Direct alcohol fuel cells(DAFCs)are powered by the alcohol electro-oxidation reaction(AOR),where an electrocatalyst with an optimal electronic structure can accelerate the sluggish AOR.Interestingly,strain engineering in hetero-catalysis offers a promising route to boost their catalytic activity.Herein,we report on a class of monodispersed ultrathin twisty PdBi alloy nanowires(TNWs)assemblies with face-centered structures that drive AORs.These thin nanowire structures expose a large number of reactive sites.Strikingly,Pd_(6)Bi_(1)TNWs show an excellent current density of 2066,3047,and 1231 mA mg_(Pd)^(-1)for oxidation of ethanol,ethylene glycol,and glycerol,respectively.The“volcano-like”behaviors observed on PdBi TNWs for AORs indicate that the maximum catalytic mass activity is a well balance between active intermediates and blocking species at the interface.This study offers an effective and universal method to build novel nanocatalysts in various applications by rationally designing highly efficient catalysts with specific strain.

Unraveling the interfacial effect of PdBi bimetallic catalysts on promoting CO_(2)electroreduction to formate

Through interface engineering and content control strategy,a PdBi bimetallic interface structure was constructed for the first time to selectively convert CO_(2)to formate with a remarkably high Faraday efficiency(FEformate)of 94%and a partial current density(jformate)of 34 mA·cm^(−2)at−0.8 V vs.reversible hydrogen electrode(RHE)in an H-cell.Moreover,the PdBi interface electrocatalyst even exhibited a high current density of 180 mA·cm^(−2)with formate selectivity up to 92%in a flow cell and could steadily operate for at least 20 h.Electrochemical in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)confirmed that the PdBi interface could greatly weaken the adsorption of*CO intermediates due to electronic and geometric effects.Density functional theory(DFT)calculations also established that the PdBi interface regulated the CO_(2)-to-formate pathway by reducing the energy barrier toward HCOOH and largely weakening the adsorption of*CO intermediates on the catalyst surface.This study reveals that the unique PdBi bimetallic interface can provide a novel platform to study the reaction mechanism through combining in-situ ATR-SEIRAS and DFT calculations.

Intermetallic PdBi aerogels with improved catalytic performance for the degradation of organic pollutants in water

It is always highly pursued to develop efficient and durable catalysts for catalytic applications.Herein,intermetallic PdBi aerogels with tunable activity were prepared successfully via a surfactant-free spontaneous gelation process.The prepared PdBi aerogels have a three-dimensional high porous structure and plentiful active sites pervaded on the ultrathin interlinked nanowires network.These unique structures,as well as the synergistic effect between Pd and Bi,can accelerate mass and electron transfer,and improve the atom utilization ratio of Pd atoms to promote the catalytic efficiency.As a proofof-concept application,the optimized Pd_(2) Bi_(1) aerogels exhibit 4.2 and 6.2 times higher catalytic activity for the reduction of 4-nitrophenol(4-NP)and methylene blue(MB)than those of commercial Pd/C,respectively.With the introduction of non-noble metal of Bi,the cost of the resulted Pd Bi aerogels can be dropped signi ficantly while the catalytic capability of Pd Bi aerogel will be improved sharply.This strategy will bring good hints to rationally design fine catalysts for various applications.

Interface-rich Au-doped PdBi alloy nanochains as multifunctional oxygen reduction catalysts boost the power density and durability of a direct methanol fuel cell device

The development of cathode oxygen reduction reaction(ORR)catalysts with high characteristics for practical,direct methanol fuel cells(DMFCs)has continuously increased the attention of researchers.In this work,interface-rich Au-doped PdBi(PdBiAu)branched one-dimensional(1D)alloyed nanochains assembled by sub-6.5 nm particles have been prepared,exhibiting an ORR mass activity(MA)of 6.40 A·mgPd^(−1) and long-term durability of 5,000 cycles in an alkaline medium.The MA of PdBiAu nanochains is 46 times and 80 times higher than that of commercial Pt/C(0.14 A·mgPt^(−1))and Pd/C(0.08 A·mgPd^(−1)).The MA of binary PdBi nanochains also reaches 5.71 A·mgPd^(−1).Notably,the PdBiAu nanochains exhibit high in-situ carbon monoxide poisoning resistance and high methanol tolerance.In actual DMFC device tests,the PdBiAu nanochains enhance power density of 140.1 mW·cm^(−2)(in O_(2))/112.4 mW·cm^(−2)(in air)and durability compared with PdBi nanochains and Pt/C.The analysis of the structure–function relationship indicates that the enhanced performance of PdBiAu nanochains is attributed to integrated functions of surficial defect-rich 1D chain structure,improved charge transfer capability,downshift of the d-band center of Pd,as well as the synergistic effect derived from“Pd-Bi”and/or“Pd-Au”dual active sites.