Catalytic conversion of ethanol to hydrogen and nanocatalyst synthesis from pulsed laser ablation using high throughput experimentation

Ethanol is a globally available renewable source for hydrogen production for automotive fuel cell applications. Combinatorial catalysis, an effective methodology for the accelerated discovery and optimization of functional materials, has been applied for the discovery of low temperature catalysts for the production of hydrogen from ethanol. Libraries of over 2000 catalytic materials were prepared by impregnating porous pellets of gamma-Al2O3, SiO2, TiO2, CeO2, Y-ZrO2 and ZnO, with individual aqueous salt solutions of 42 elements from the periodic table. Ethanol steam reforming activities and H2 selectivities of these single and binary catalysts were then evaluated using a computerized array channel microreactor system and mass spectrometry under identical operating conditions of 300°C, 1 atm, GHSV of 60,000 h-1, 2% C 2H5OH and 12% H2O in helium carrier gas. The systematic investigation provided both confirmatory results and produced new leads of superior catalytic materials. Pt/TiO2 and Pt/CeO2 were the most significant new leads, both of which gave the highest ethanol conversions (+90%) and hydrogen selectivities (about 30%) at 300°C among all the single component catalytic materials explored. About 15% improvement of H2 production was observed on Pt binaries with some noble metals such as Rh and Pd. Cu-Ni on SiO2 exhibited highest activity among all non-noble binary catalysts.; It is well established that activities and selectivities of a catalyst are mainly determined by particle sizes and their distribution. A high-throughput pulsed laser ablation (HT-PLA) system was developed to rapidly prepare uniformly sized single and multi-metallic nanoparticles with different diameters for catalytic applications. Rh, Au, bimetallic Rh/Pt and trimetallic Rh/Pt/Au nanoparticles were synthesized from targets. Nanoparticles exhibited crystallinity and uniformity in size. The supported Rh nanoparticles created by HT-PLA were also screened for their catalytic activities and selectivities for the partial oxidation of propylene. The preliminary results showed that laser ablated nanoparticles possessed measurable catalytic properties.