Synthesis of palladium-rhodium bimetallic nanoparticles for formic acid dehydrogenation

Herein, we report for the first time synthesis of preformed bimetallic Pd-Rh nanoparticles with different Pd:Rh ratios (nominal molar ratio: 80–20, 60–40, 40–60, 20–80) and corresponding Pd Rh monometallic ones by sol immobilization using polyvinyl alcohol (PVA) as protecting agent NaBH4 reducing agent, carbon nanofibers high graphitization degree (HHT) desired support. The synthesized catalysts were characterized means Transmission Electron Microscopy (TEM) inductively coupled plasma optical emission spectroscopy (ICP-OES). TEM shows that average particle size is range 3–4 nm, presence few large agglomerated nanoparticles. For catalysts, EDX-STEM analysis individual demonstrated random-alloyed even in all cases content lower than nominal one (calculated 90–10, 69–31, 49–51, 40–60). catalytic performance was evaluated liquid phase dehydrogenation formic acid to H2. It found ratio strongly influences performance. Pd-rich more active Rh-rich ones, highest activity observed Pd90:Rh10 (1792 h?1), whereas Pd69:Rh31 (921 h?1) resulted most stable during recycling tests. Finally, chosen a representative sample liquid-phase hydrogenation muconic hydrogen donor, showing good yield adipic acid.