Pd(0) Nanoparticles Decorated on Graphene Nanosheets (GNS): Synthesis, Definition and Testing of the Catalytic Performance in the Methanolysis of Ammonia Borane at Room Conditions

Abstract

Pd(0) nanoparticles (NPs) decorated on graphene nanosheets (GNS), Pd/GNS, have been synthesized by classical wet‐chemical method and reduced by using sodium borohydride. The definition of the Pd/GNS nanocatalyst by the combination methods reveals that the formation of well‐dispersed highly crystalline 3.68 ± 0.35 nm Pd(0) NPs on the surface of GNS. The Pd/GNS nanocatalyst was tested as a catalyst in the hydrogen production reaction via methanolysis of ammonia‐borane. Compared with the heterogeneous catalyst systems used for this reaction up to now in the literature, it has been understood that this is one of the best catalysts in terms of high efficiency (TOF=101.5 mol H2 mol catalyst−1 min−1, 253.75 min−1 corrected for the surface atoms), low activation energy (46 kJ mol−1) and total conversion (>99%) at room conditions. The more important is the remarkable stability of Pd/GNS against to agglomeration make Pd/GNS recyclable catalyst for the methanolysis of AB. Pd/GNS nanocatalyst retains 74.6% of its initial activity with 95.8% of conversion even at 5th recycle in the methanolysis of AB. Finally, the methanolysis reaction was carried out at various temperatures with different catalyst and substrate concentrations to write the rate equation and determine other activation parameters (ΔH# and ΔS#).

Ammonia Borane: An Extensively Studied, Though Not Yet Implemented, Hydrogen Carrier

“…The reader may refer to a recent review article [148]. A variety of nanostructured transition metal catalysts (also called nanocatalysts) have been developed, with a special focus on copper [149][150][151][152], cobalt [153] and cobalt-palladium combinations [154,155], nickel [153,156,157], palladium [158][159][160], rhodium [161][162][163][164] and ruthenium [165][166][167].…”

Rh (0) nanoparticles impregnated on two‐dimensional transition metal carbides, MXene , as an effective nanocatalyst for ammonia‐borane hydrolysis

“…12,13 At ambient conditions and when a suitable catalyst is used, AB, an extraordinary structure containing both N-H (protic) and B-H (hydridic) bonds and a strong B-N bond, releases hydrogen. 14 AB generates the hydrogen stored in its structure through hydrolysis, [15][16][17][18] methanolysis, [19][20][21] thermolysis, 22 and dehydrogenation or dehydrocoupling.23 Among these methods, thermolysis is not preferred because it requires high-temperature, hydrolysis is preferable because it is both easy and has suitable reaction for fuel cell applications. The hydrolysis reaction of AB (1) releases 3.0 equivalents of H 2 per AB under mild conditions in the presence of a suitable catalyst.…”

Methanolysis of ammonia borane using binder‐free hierarchical Co@Ni metal‐organic framework nanocolumn arrays catalyst for hydrogen generation

“…Karatas et al developed Pd (0) nanoparticles on graphene nanosheets using the wet‐chemical method and reduced using sodium borohydride. The prepared catalysts were performed hydrogen generation by AB methanolysis with higher efficiency of TOF value (253.75 min −1 ) at room temperature 17 …”

“…The prepared catalysts were performed hydrogen generation by AB methanolysis with higher efficiency of TOF value (253.75 min À1 ) at room temperature. 17 Metal-organic framework (MOF) comprises coordination metal-ion clusters and organic ligand clusters. Recently, MOFs have been widely used due to their higher surface area and porosity, abundant active sites, and higher-order nanoarchitectures.…”