Transition Metal Phosphides (TMP) as a Versatile Class of Catalysts for the Hydrodeoxygenation Reaction (HDO) of Oil-Derived Compounds

Abstract

Hydrodeoxygenation (HDO) reaction is a route with much to offer in the conversion and upgrading of bio-oils into fuels; the latter can potentially replace fossil fuels. The catalyst’s design and the feedstock play a critical role in the process metrics (activity, selectivity). Among the different classes of catalysts for the HDO reaction, the transition metal phosphides (TMP), e.g., binary (Ni2P, CoP, WP, MoP) and ternary Fe-Co-P, Fe-Ru-P, are chosen to be discussed in the present review article due to their chameleon type of structural and electronic features giving them superiority compared to the pure metals, apart from their cost advantage. Their active catalytic sites for the HDO reaction are discussed, while particular aspects of their structural, morphological, electronic, and bonding features are presented along with the corresponding characterization technique/tool. The HDO reaction is critically discussed for representative compounds on the TMP surfaces; model compounds from the lignin-derivatives, cellulose derivatives, and fatty acids, such as phenols and furans, are presented, and their reaction mechanisms are explained in terms of TMPs structure, stoichiometry, and reaction conditions. The deactivation of the TMP’s catalysts under HDO conditions is discussed. Insights of the HDO reaction from computational aspects over the TMPs are also presented. Future challenges and directions are proposed to understand the TMP-probe molecule interaction under HDO process conditions and advance the process to a mature level.

Nickel—Alumina Catalysts for the Transformation of Vegetable Oils into Green Diesel: The Role of Preparation Method, Activation Temperature, and Reaction Conditions

“…This decrease concerns all kinds of acid sides. It is well known that acid sites play an important role in the mechanism of the triglyceride SDO [ 12 , 38 ]. Papanikolaou et al [ 12 ], working on Ni/zeo-type catalysts, revealed that the proximity between the acidic and the hydrogenation functions led to catalysts with high selectivity to diesel range products enhancing both deCOx and HDO pathways.…”

Versatile Janus Architecture for Electrocatalytic Applications

“…TMP are created through the alloying of TM with P atoms, whereby the P atoms can influence the electronic conductivity of the material, and thus contribute to the intrinsic electrocatalytic activity of the material. [ 77,78 ] The earliest reported Janus TMP is the Janus Ni 2 P by Stern et al. as active electrocatalysts for H 2 production from both acidic and alkaline waters in 2015.…”

“…TMP are created through the alloying of TM with P atoms, whereby the P atoms can influence the electronic conductivity of the material, and thus contribute to the intrinsic electrocatalytic activity of the material. [77,78] The earliest reported Janus TMP is the Janus Ni 2 P by Stern et al as active electrocatalysts for H 2 production from both acidic and alkaline waters in 2015. [79] Since then, there has been a surge in Janus TMP for HER electrocatalytic application in view of their excellent HER electrocatalytic activity, which is close to that of state-of-theart Pt/C.…”

Direct deoxygenation reaction of oxygenated model compounds by biomass pyrolysis on the Ni5P4(001) surface: a computational study

“…9 Therefore, in this study, the guaiacol molecule was also employed to study the DDO reaction because of its higher coking tendency than other phenolic compounds, and also it is a challenging molecule to be totally deoxygenated owing to the co-existence of methoxy and hydroxyl functional groups. 10,11 It is noteworthy to mention that phenol is the OH derivative of benzene and guaiacol is the CH 3 -substituted derivative of phenol, and thereby this variation in molecular structure dictates their different adsorption energetics and reaction kinetics on the Ni 5 P 4 (001) surface.…”