TY - JOUR
T1 - Mechanistic Insights into Polypropylene Hydrogenolysis Using Ni/Al2O3 Catalysts
AU - Huang, Xiyan
AU - Meng, Weixin
AU - Acevedo-Guzmán, Diego A.
AU - Wang, Hongqi
AU - Sridharan, Balaji
AU - Rudolf, Petra
AU - Heeres, Hero Jan
AU - Xie, Jingxiu
N1 - Publisher Copyright:
© 2025 The Authors. Published by American Chemical Society.
PY - 2025/1/23
Y1 - 2025/1/23
N2 - Catalytic hydrogenolysis is emerging as an attractive strategy for converting polyolefins into high-value hydrocarbon liquids. A key challenge in catalytic hydrogenolysis is the high methane yield. Recently, Ni-based catalysts have shown promise as a cost-effective alternative to noble metals in polyolefin hydrogenolysis. In this study, three alumina-supported Ni catalysts (12-13 wt % Ni) were prepared using acidic, neutral, and basic γ-Al2O3 via impregnation. The resulting Ni/A-Al2O3, Ni/N-Al2O3, and Ni/B-Al2O3 catalysts were used to investigate reaction pathways in n-hexadecane and isotactic polypropylene hydrogenolysis. Experiments conducted in a batch autoclave at 300 °C with 30 bar of H2 showed that Ni/B-Al2O3 exhibited the highest reactivity, 5 h for n-hexadecane and 30 h for polypropylene, respectively. Using n-hexadecane as a model compound for hydrogenolysis, we attributed the origin of methane selectivity to terminal C-C bond scission, occurring through both single-step and cascade mechanisms. Detailed product analysis (GC-FID, GPC, and NMR) and comprehensive catalyst characterization revealed the origins of varied activity and product distribution in the hydrogenolysis of n-hexadecane and polypropylene. The increased ratio of tetrahedrally coordinated Ni2+ to metallic Ni0, attributed to stronger metal-support interactions, along with stronger surface basicity, promotes terminal C-C scission, leading to enhanced hydrogenolysis reactivity.
AB - Catalytic hydrogenolysis is emerging as an attractive strategy for converting polyolefins into high-value hydrocarbon liquids. A key challenge in catalytic hydrogenolysis is the high methane yield. Recently, Ni-based catalysts have shown promise as a cost-effective alternative to noble metals in polyolefin hydrogenolysis. In this study, three alumina-supported Ni catalysts (12-13 wt % Ni) were prepared using acidic, neutral, and basic γ-Al2O3 via impregnation. The resulting Ni/A-Al2O3, Ni/N-Al2O3, and Ni/B-Al2O3 catalysts were used to investigate reaction pathways in n-hexadecane and isotactic polypropylene hydrogenolysis. Experiments conducted in a batch autoclave at 300 °C with 30 bar of H2 showed that Ni/B-Al2O3 exhibited the highest reactivity, 5 h for n-hexadecane and 30 h for polypropylene, respectively. Using n-hexadecane as a model compound for hydrogenolysis, we attributed the origin of methane selectivity to terminal C-C bond scission, occurring through both single-step and cascade mechanisms. Detailed product analysis (GC-FID, GPC, and NMR) and comprehensive catalyst characterization revealed the origins of varied activity and product distribution in the hydrogenolysis of n-hexadecane and polypropylene. The increased ratio of tetrahedrally coordinated Ni2+ to metallic Ni0, attributed to stronger metal-support interactions, along with stronger surface basicity, promotes terminal C-C scission, leading to enhanced hydrogenolysis reactivity.
UR - http://www.scopus.com/inward/record.url?scp=85214563847&partnerID=8YFLogxK
U2 - 10.1021/acs.energyfuels.4c04726
DO - 10.1021/acs.energyfuels.4c04726
M3 - Article
AN - SCOPUS:85214563847
SN - 0887-0624
VL - 39
SP - 1721
EP - 1734
JO - Energy and Fuels
JF - Energy and Fuels
IS - 3
ER -