An amorphous Ni-Fe catalyst for electrocatalytic dehydrogenation of alcohols to value-added chemicals

As for the hydrogen production process via electrocatalytic water splitting, the green and sustainable electro-oxidation of organic molecules at the anode is thermodynamically more favourable than the oxygen evolution reaction (OER). Here, we proposed for the first time to replace the OER process by the oxidation of N-Boc-4-piperidine methanol (BPM), via a parallel reaction, which finally leads to the green production of N-Boc-4-piperidine carboxaldehyde (BPC). The amorphous NiFeO(OH) nanospheres with rich valence states were adopted as the anode catalyst, with creation of more active sites. The gas chromatography results showed that nearly all the BPM converted to BPC after 15 h reaction. The electrochemical tests showed that the Faraday efficiency (FE) approaches nearly 100% when the charge transfer is approximately equal to the theoretical charge. This work reports a new process for the alcohol oxidation, providing a valuable green organic synthesis process.

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

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.

The role of Ni sites located in mesopores for the selectivity of anisole hydrodeoxygenation

A highly-dispersed Ni catalyst with an increased number of Ni sites selectively distributed in the mesopores of HBEA has been developed and applied in anisole hydrodeoxygenation (HDO) in a continuous-flow...