Experimental and computational study on roles of WOx promoting strong metal support promoter interaction in Pt catalysts during glycerol hydrogenolysis

Tinnakorn Saelee; Poonnapa Limsoonthakul; Phakaorn Aphichoksiri; Meena Rittiruam; Mongkol Lerdpongsiripaisarn; Takanori Miyake; Hiromi Yamashita; Kohsuke Mori; Yasutaka Kuwahara; Supareak Praserthdam; Piyasan Praserthdam

doi:10.1038/s41598-020-79764-3

Experimental and computational study on roles of WO_x promoting strong metal support promoter interaction in Pt catalysts during glycerol hydrogenolysis

Sci Rep. 2021 Jan 12;11(1):530. doi: 10.1038/s41598-020-79764-3.

Authors

Tinnakorn Saelee^{1

2

3}, Poonnapa Limsoonthakul^{2

3}, Phakaorn Aphichoksiri^{1

2

3}, Meena Rittiruam^{1

2

4}, Mongkol Lerdpongsiripaisarn^{1

2

3}, Takanori Miyake⁵, Hiromi Yamashita⁶, Kohsuke Mori⁶, Yasutaka Kuwahara⁶, Supareak Praserthdam^{7

8}, Piyasan Praserthdam²

Affiliations

¹ High-Performance Computing Unit (CECC-HCU), Centre of Excellence on Catalysis and Catalytic Reaction Engineering (CECC), Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand.
² Centre of Excellence on Catalysis and Catalytic Reaction Engineering (CECC), Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand.
³ Saelee Research Group, Chulalongkorn University, Bangkok, 10330, Thailand.
⁴ Rittiruam Research Group, Chulalongkorn University, Bangkok, 10330, Thailand.
⁵ Faculty of Environmental and Urban Engineering Department of Chemical, Energy and Environmental Engineering, Kansai University, Suita, Osaka, 564-8680, Japan.
⁶ Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 1-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
⁷ High-Performance Computing Unit (CECC-HCU), Centre of Excellence on Catalysis and Catalytic Reaction Engineering (CECC), Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand. supareak.p@chula.ac.th.
⁸ Centre of Excellence on Catalysis and Catalytic Reaction Engineering (CECC), Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand. supareak.p@chula.ac.th.

Abstract

Biodiesel is of high interest due to increased demand for energy with the concern regarding more sustainable production processes. However, an inevitable by-product is glycerol. Hence, the conversion of this by-product to higher-value chemicals, especially 1,3-propanediol (1,3-PDO) via glycerol hydrogenolysis reaction, is one of the most effective pathways towards a profitable process. In general, this process is catalyzed by a highly active Pt-based catalyst supported on γ-Al₂O₃. However, its low 1,3-PDO selectivity and stability due to surface deactivation of such catalysts remained. This led to the surface modification by WO_x to improve both the selectivity by means of the increased Brønsted acidity and the stability in terms of Pt leaching-resistance. Hence, we applied experimental and density functional theory (DFT)-based techniques to study the fundamentals of how WO_x modified the catalytic performance in the Pt/γ-Al₂O₃ catalyst and provided design guidelines. The effects of WO_x promoter on improved activity were due to the shifting of the total density of states towards the antibonding region evident by the total density of states (TDOS) profile. On the improved 1,3-PDO selectivity, the main reason was the increasing number of Brønsted acid sites due to the added WO_x promoter. Interestingly, the stability improvement was due to the strong metal-support interaction (SMSI) that occurred in the catalyst, like typical high leaching-resistant catalysts. Also, the observed strong metal-support-promoter interaction (SMSPI) is an additional effect preventing leaching. The SMSPI stemmed from additional bonding between the WO_x species and the Pt active site, which significantly strengthened Pt adsorption to support and a high electron transfer from both Pt and Al₂O₃ to WO_x promoter. This suggested that the promising promoter for our reaction performed in the liquid phase would improve the stability if SMSI occurred, where the special case of the WO_x promoter would even highly improve the stability through SMSPI. Nevertheless, various promoters that can promote SMSPI need investigations.