Palladium acetylacetonate

Palladium acetylacetonate (Pd(acac)₂, 99%), sodium tetrachloropalladate (II) (Na₂PdCl₄, 98%), palladium(II) acetate (Pd(C₂H₃O₂)₂, 99%), trioctylphosphine (TOP, 90%), oleylamine (OAm, >70%) and N-methyl-2-pyrrolidinone (NMP, ACS reagent grade) were all purchased from Sigma Aldrich. Graphite power (SP grade) was purchased from Sinopharm Chemical Reagent Co., Ltd., China. All chemical reagents were used without further purification.

The GaOOH nanorods were synthesized using a typical solvothermal method, 1050 mg of sodium dodecylbenzenesulfonate and 3850 mg of gallium nitrate hydrate were dissolved in 60 ml of deionized water under vigorous stirring. The mixture was stirred in air for 3 min to form a white slurry. Then, the 1.5 M sodium hydroxide (Sinopharm Chemical Reagent, CO) was dropwise added to the solution until the pH was 7 to 8. Then, the mixture was stirred for about 5 min to obtain a white flocculated colloid. Then, the suspension was transferred into a 100-ml autoclave, sealed, and maintained at 140°C for 8 hours. The acquired mixtures were filtered and washed three times with deionized water after being lowered to room temperature. The obtained white powder was dried in the oven at 80°C for 12 hours and then calcined at 300, 500, 700, and 900°C for 2 hours.
The supported catalyst was prepared through a typical wetness impregnation method, during which the palladium acetylacetonate (Sigma-Aldrich) and α-Ga₂O₃ nanorods were used. The loading content of Pd was controlled at 5.0 weight %. After calcination at 500°C in air for 2 hours, the samples were reduced at 100° to 600°C with a 100°C interval in 50% H₂/Ar for 2 hours to obtain the metallic Pd-based catalysts.

Palladium acetylacetonate (Pd(acac)₂, 99%), platinum acetylacetonate (Pt(acac)₂, 97%), triphenylphosphine (TPP, 99%), borane tert-butylamine complex (BTB, 97%), trioctylphosphine oxide (TOPO, technical grade, 90%), oleylamine (OAm, technical grade, 70%), tetrabutylammonium bromide (TBAB, 99%) and Nafion perfluorinated ion-exchange resin (5 wt% solution in a lower aliphatic alcohol/H₂O mixture that contains 15–20% water) were all purchased from Sigma-Aldrich. Acetic acid (CH₃COOH, 99.7%) and methanol (CH₃OH, 99%) were purchased from Wako Pure Chemical Industries Ltd. Commercial Pt/C (50% platinum on Vulcan XC-72) was purchased from Fuel Cell Store. Carbon black (Vulcan XC-72) was purchased from Moubic Inc. Polishing alumina (0.05 μm) was purchased from BAS Inc. All the chemicals were used as received without further purification.