A Comprehensive Review of Experimental Parameters in Bio-oil Upgrading from Pyrolysis of Biomass to Biofuel Through Catalytic Hydrodeoxygenation

Simultaneous Pd Nanoparticle Deposition and Enhancement in the Surface Oxygen Vacancy of Bi2MoO6 Nanoflakes for Room Temperature Vanillin Hydrodeoxygenation

“…This route emerged as an efficient way to reduce the oxygen content in biomass-derived chemicals and provides high selectivity and productivity. , Nonetheless, the selection of a suitable and active catalyst is always required for this purpose. The HDO process has been widely studied in biomass processing, and much research has been devoted to this objective. − Lignin, one of the major components of lignocellulose biomass, is the source of various phenolic compounds used in various applications. − For example, lignin-derived vanillin is an important chemical used in various applications such as flavoring agents, food, perfumes, and pharmaceuticals. − The vanillin structure is composed of a benzene ring, methoxy, hydroxyl, and aldehyde groups. Catalytic HDO of vanillin allows the production of various important chemicals, such as hydrogenolysis and demethoxylation of vanillin yielding 2-methoxy-4-methyl phenol (MMP) and 4-methyl phenol, respectively .…”

“…The literature survey demonstrates that a series of noble metal-based catalysts including Au, Pd, Ru, Rh, and Pt have been reported so far for vanillin HDO to MMP. 11,13,31 These metals have been supported over various supports such as zeolites, metal oxides, g-C 3 N 4 , carbon, MOFs, etc. 11,13 Moreover, the role of oxygen vacancies in deoxygenation reactions has also been established in the literature.…”

“…Furthermore, under harsh reaction conditions, over-hydrogenation and C–C bond cleavage are more likely to happen. , Therefore, a catalyst design that could be operated under milder conditions with high MMP selectivity is highly desirable. The literature survey demonstrates that a series of noble metal-based catalysts including Au, Pd, Ru, Rh, and Pt have been reported so far for vanillin HDO to MMP. ,, These metals have been supported over various supports such as zeolites, metal oxides, g-C 3 N 4 , carbon, MOFs, etc. , Moreover, the role of oxygen vacancies in deoxygenation reactions has also been established in the literature. , Various catalytic systems based on metal oxides such as Co 3 O 4 , MoO 3 , Al 2 O 3 , CeO 2 , Nb 2 O 5 , and Ni–Co oxides have low barriers for oxygen vacancy formation and have been reported for vanillin HDO. − These oxygen vacancies could be utilized as nucleation sites for metal particles and provide high metal dispersion on the surface . However, these catalytic systems require stringent reaction conditions; therefore, a novel catalytic system needs to be developed for the efficient and selective conversion of vanillin.…”

“…11,13,31 These metals have been supported over various supports such as zeolites, metal oxides, g-C 3 N 4 , carbon, MOFs, etc. 11,13 Moreover, the role of oxygen vacancies in deoxygenation reactions has also been established in the literature. 32,33 Various catalytic systems based on metal oxides such as Co 3 O 4 , MoO 3 , Al 2 O 3 , CeO 2 , Nb 2 O 5 , and Ni− Co oxides have low barriers for oxygen vacancy formation and have been reported for vanillin HDO.…”

Hydrodeoxygenation of Pyrolysis Oil in Supercritical Ethanol with Formic Acid as an In Situ Hydrogen Source over NiMoW Catalysts Supported on Different Materials

“…Different methods have been used to improve bio-oil quality. These include emulsification [11], hydrodeoxygenation (HDO) [12], steam reforming [13], catalytic cracking [14], and supercritical fluid treatment [15]. HDO is a promising method to improve bio-oil quality by removing oxygen atoms at 300-450 • C, usually in a hydrogen donor solvent such as tetralin and under high hydrogen gas pressure (up to 200 bar) [16][17][18].…”