Aqueous-phase reforming of ethylene glycol over supported Pt and Pd bimetallic catalysts

Abstract

Aqueous-phase reforming of 10 wt% ethylene glycol solutions was studied at temperatures of 483 and 498 K over Pt-black and Pt supported on TiO 2 , Al 2 O 3 , carbon, SiO 2 , SiO 2-Al 2 O 3 , ZrO 2 , CeO 2 , and ZnO. High activity for the production of H 2 by aqueous-phase reforming was observed over Pt-black and over Pt supported on TiO 2 , carbon, and Al 2 O 3 (i.e., turnover frequencies near 8-15 min ÿ1 at 498 K); moderate catalytic activity for the production of hydrogen is demonstrated by Pt supported on SiO 2-Al 2 O 3 and ZrO 2 (turnover frequencies near 5 min ÿ1); and lower catalytic activity is exhibited by Pt supported on CeO 2 , ZnO, and SiO 2 (H 2 turnover frequencies lower than about 2 min ÿ1). Pt supported on Al 2 O 3 , and to a lesser extent ZrO 2 , exhibits high selectivity for production of H 2 and CO 2 from aqueous-phase reforming of ethylene glycol. In contrast, Pt supported on carbon, TiO 2 , SiO 2-Al 2 O 3 and Pt-black produce measurable amounts of gaseous alkanes and liquid-phase compounds that would lead to alkanes at higher conversions (e.g., ethanol, acetic acid, acetaldehyde). The total rate of formation of these byproducts is about 1-3 min ÿ1 at 498 K. An important bifunctional route for the formation of liquid-phase alkane-precursor compounds over less selective catalysts involves dehydration reactions on the catalyst support (or in the aqueous reforming solution) followed by hydrogenation reactions on Pt.

Upgrading Lignocellulosic Biomasses: Hydrogenolysis of Platform Derived Molecules Promoted by Heterogeneous Pd-Fe Catalysts

“…In the first step, Pd is supported by IWi and, in a subsequent stage, a Fe metal salt (generally nitrate) is added, also by IWi, to prepare the bimetallic catalyst. The sequential impregnation technique was used by Huber et al [78,130], to prepare Pd-Fe bimetallic catalysts supported on Al 2 O 3 . By the same procedure a Pd-Fe/Zr-P bimetallic catalyst has been successfully obtained [140].…”

“…Specifically, results obtained in important "green and sustainable" reactions will be presented including: aqueous-phase reforming [128][129][130], hydrogenolysis [131][132][133][134][135][136] and CTH [137,138] of C6-C2 polyols, hydrogenolysis and transfer hydrogenolysis of furfural [139,140], hydrodeoxygenation of phenol derivatives [141,142], HDO and CTH of aromatic ethers [143][144][145]. All these reactions will be discussed in details with the aim to show the unicity of heterogeneous Pd-Fe catalysts that are suitable for a wide reductive valorization processes of all constituent components of lignocellulosic biomasses having the potential to be successfully used in modern biorefineries to produce simple bulk compounds.…”

Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysts, and Engineering

“…More than 500 different mono-and bimetallic catalytic materials were screened using the high-throughput reactor, and inexpensive nonprecious metal catalysts and highly active precious metal catalysts were identified. 271,278 The activity of Pt catalysts can be improved further by adding Ni, Co, or Fe to a Pt/Al 2 O 3 catalyst. 278 Alumina-supported PtNi and PtCo catalysts, with Pt/Co or Pt/Ni atomic ratios ranging from 1:1 to 1:9 had the highest turnover frequencies for H 2 production (TOF H2 , defined as moles of H 2 per mole of surface site counted by CO chemisorption) with values of 2.…”

“…271,278 The activity of Pt catalysts can be improved further by adding Ni, Co, or Fe to a Pt/Al 2 O 3 catalyst. 278 Alumina-supported PtNi and PtCo catalysts, with Pt/Co or Pt/Ni atomic ratios ranging from 1:1 to 1:9 had the highest turnover frequencies for H 2 production (TOF H2 , defined as moles of H 2 per mole of surface site counted by CO chemisorption) with values of 2. Ni-based catalysts are active for APR; however, they have poor selectivity and stability.…”

Gasification of Kenaf Hydrolysate and Optimization by Response Surface Methodology

“…Elde edilen bu gaz ürünleri, elektrik, hidrojen, kimyasallar ve sıvı nakil yakıtları üretmek için kullanılabilir. Gazlaştırma teknikleri arasında subkritik su ve süperktirik su (Williams and Onwudili, 2005) sulu faz reformlama (Huber et al, 2006), buhar faz reformlama (Rioche et al, 2005) bulunmaktadır. Buna tekniklere ek olarak sulu faz reformlama prosesinden elde edilenden çok daha yüksek verimle hidrojen üretimi konusunda teknik geliştirilmiştir (Hasanoğlu et al, 2016).…”