Investigating the Synergistic Effects between Ni and Me Species over Nano-Nickel-Based Catalyst Ni-Me/HZSM-5 (Me = Co, Cu, La) on the In Situ Catalytic Pyrolysis of Distillers' Dried Grains with Solubles (DDGS)

High Resolution Image Download MS PowerPoint Slide To investigate the synergistic effects between Ni and Me over Ni−Me/HZSM-5 on the pyrolysis of distillers’ dried grains with solubles (DDGS), the related testing experiments and characterizations of XRD, NH 3 -TPD, H 2 -TPR, and (HR)TEM were performed. According to experimental results, it was supposed that, with the pyrolytic time increasing, the reduction reaction reached dynamic equilibrium leading to a Cu−Co−La decreasing sequence of the amount and strength of acidity, which led to the relative content of organosilicon compounds in bio-oil decreasing with Ni−Cu/HZSM-5 (60.81%), Ni−Co/HZSM-5 (43.42%), and Ni−La/HZSM-5 (42.11%) and that of long-chain carboxylic acid and ester increasing with Ni−Cu/HZMS-5 (4.83%), Ni−Co/HZSM-5 (8.35%), and Ni−La/HZSM-5 (12.93%). The weaker the strong acidity, the more phenolic compounds generated. As regards Ni−Co/HZSM-5, apart from its intensity of acidity, the relatively uniform and biggest pore size might also be responsible for its strongest capability of generating aromatic compounds. In turn, for Ni−Cu/HZSM-5, its low utilization rate of active sites might be related to its weakest capability of producing phenolic compounds. Ni−Cu/HZSM-5 possessed moderately strong abilities to promote the catalytic reforming of methane with carbon dioxide or water vapor with Ni and Cu grippers; Cu inveigled electrons and transferred to Ni creating Ni δδδ− (the atomically dispersed electron-rich nickel species). Thus, the intermediates easily captured electrons from Ni δδδ− to release more H 2 . The effect from Ni−Co/HZSM-5 was similar but inferior to Ni−Cu/HZSM-5 in synergism; for Ni−La/HZSM-5, despite the weakest acidity and lack of synergistic effect of electrons transferring between Ni δδδ− and La δ−, the maximum scattering of Ni(La) species, the strongest gripper of La 2 O 3 for adsorbing CO 2, and the highest ratio of A/C (6.89) synergistically generated H 2 -rich pyrolytic gas with 78.29 vol % of H 2 . This work may encourage researchers and wineries to seek the synergism between specific elements for exploring novel catalysts to convert waste biomass materials into high-value-added products and embarking on sustainable development paths.