The Preparation And Research Of Efficient Catalysts Of Ag_0.1Pd_0.9/rGO And Ag_0.2Au_0.4Pd_0.4/rGO For Hydrogen Generation From Formic Acid

Hydrogen (H2), which is widely accepted as a promising energy carrier fortransport/mobile applications may play an important role in renewable energytechnologies in the future. However, due to the extremely low critical point and very lowdensity of H2gas, efficient storage of H2remains a bottleneck for the H2based fuel celleconomy. As an alternative, chemical H2storage has been attracting considerableattention. Formic acid (FA, HCOOH), one of the major products formed in biomassprocessing, is nontoxic and highly stable with a high H2content (4.4%) at roomtemperature, making it a safe and convenient H2carrier in fuel cells for portable use. FAcan be decomposed to H2and CO2via a dehydrogenation pathway(HCOOH(l)â†'H2(g)+CO2(g),â–³G298K=-35.0kJ mol-1) in the presence of a suitablecatalyst. However, the undesirable dehydration pathway (HCOOH(l)â†'H2O(l)+CO(g),â–³G298K=-14.9kJ mol-1) to generate carbon monoxide (CO), which is a fatal poison tocatalysts in fuel cells, should be avoided by adjusting the catalysts, pH values of thesolutions, as well as the reaction temperatures.Recently, the decomposition of formic acid has been intensely investigated forhydrogen generation, particularly in the area of reforming catalyst development. Forexample, metal complex-based heterogeneous catalysts have been reported to havehigh performance for the formic acid decomposition at near-ambient temperatures.Generally, heterogeneous catalysts are easy to use widely because of the ease to becontrolled, retrieved, and recycled and there is a strong desire to developheterogeneous catalysts with high activity and selectivity for the formic aciddecomposition under mild conditions.Metallic particles with ultrafine sizes have attracted tremendous research interest because of their unique catalytic properties compared to their bulk counterparts due tothe high surface area and the number of edge and corner atoms. However, small particles,especially on the nanoscale, are frequently subjected to the problem of aggregation,resulting from their high surface energy, which usually leads to the serious reduction oftheir catalytic properties. To avoid this issue, various types of support materials havebeen employed to uniformly disperse the nanoparticles (NPs). Graphene, a single-layercarbon material, attracts tremendous attention owing to its high conductivity (103–104Sm-1), huge theoretical surface area (2600m2g-1), unique graphitized basal plane structure,and potentially low manufacturing costs. With these advantages, graphene-basednanomaterials are being explored for use in sensors, electronics, electrochemical energystorage, efficient catalysts, etc. In catalytic studies, its close contact with metal NPs isbelieved to play a significant role in the activity enhancement of the catalyst. Thus,graphene is a promising candidate as an ideal substrate to anchor various functionalgroups with accessible active sites for high performance catalysis.Herein we report a facile, eco-friendly, one-pot method for the synthesis of areduced graphene oxide (rGO) supported alloy nanoparticle catalyst (Ag0.1Pd0.9/rGO andAg0.2Au0.4Pd0.4/rGO) by simultaneous reduction of metal precursor and graphene oxide(GO). The prepared catalysts exhibit the100%H2selectivity, highest activity, andexcellent stability toward H2generation from FA at room temperature under ambientconditions.