Highly selective hydrogen production from propane by Ru-Ni core-shell nanocatalyst deposited on reduced graphene oxide by sequential chemical vapor deposition

A narrow temperature window (160 degrees C-190 degrees C) was identified for the selective deposition of Ru on Ni supported on reduced graphene oxide (rGO) through a sequential chemical vapor deposition (CVD) method. Cyclopentadiene and cyclopentene were identified as decomposition products of nickelocene CVD on rGO, whereas only methane was detected in gaseous products from ruthenocene CVD. Heat treatment converted the selectively deposited Ru on Ni/rGO into Ru-Ni core-shell bimetallic system on the surface of rGO as confirmed by high-resolution transmission electron microscopy. The Ru-Ni/rGO thus prepared produced hydrogen with high selectivity in propane steam reforming performed in the temperature range of 350 degrees C to 850 degrees C. Addition of 3.6% Ru against Ni supported on rGO improved the turnover frequency (TOF) of propane up to 70% to 100% compared to the Ni/rGO catalyst at lower temperatures (350 degrees C-450 degrees C). The presence of Ru lowered the activation energy of propane SR from 65.7 kJ mol(-1) for Ni/rGO to 48.7 kJ mol(-1) for Ru-Ni/rGO catalyst.