Hydrogenation and hydrodeoxygenation of aromatic lignin monomers over Cu/C, Ni/C, Pd/C, Pt/C, Rh/C and Ru/C catalysts: Mechanisms, reaction micro-kinetic modelling and quantitative structure-activity relationships
Artikel i vetenskaplig tidskrift, 2019

In this integrated in silico and experimental study, the activity, selectivity and mechanisms of commercially-available noble and transition metal heterogeneous catalysts, on neutral (carbon) support were investigated for hydrodeoxygenation (HDO) of eugenol. The latter was selected as a model compound of lignin building blocks. An influence of the process operating conditions (temperature, pressure and initial solid loading) on the reaction pathway and product distribution was studied as well. The previously-proposed reaction network for phenols HDO over Ru/C was found valid also for other platinum-group- (Pd, Pt and Rh) and non-noble (Cu or Ni) metallic clusters supported on C. Ru/C system exhibited the best HDO turnover performance, followed by the Rh/C, which especially demonstrated an excellent hydrogenation activity. Pt and Pd showed low deoxygenation and moderate hydrogenation activity. Kinetic parameters for all reactions on the surface were determined for all tested metals with a micro-kinetic model, by regression analysis on the foundation of 5760 experimentally-determined concentration values. Computation took into account resistances caused by transport phenomena, adsorption/desorption kinetics, and especially surface and bulk reaction kinetics. Ratio between adsorption and desorption rate constants for dissolved saturated, aromatic and hydrogen species were predicted, indicating a notable coverage effect on the catalyst reactivity. The saturation of functionalised benzene ring was approximately 3-, 11-, 32-, 10-, and 6-times faster than the C–O hydrogenolysis over ruthenium, platinum, palladium, rhodium and nickel, respectively. Methoxy group removal is easier from aromatics, compared to aliphatic species and also compared to the hydroxyl group removal. The heteroatom bond breaking for 2-methoxy-4-propylcyclohexanol proceed mostly via catechol-type diol formation, and subsequently, de-hydroxylation, particularly observable on Pt.

Bio-based chemicals

Biomass deoxygenation

Micro-kinetic modelling

Lignin valorisation

Hydrogenation and hydrocracking

Bio-refining to aromatics

Författare

A. Bjelić

National Institute of Chemistry Ljubljana

M. Grilc

National Institute of Chemistry Ljubljana

Matej Hus

National Institute of Chemistry Ljubljana

Chalmers, Fysik, Kemisk fysik

B. Likozar

National Institute of Chemistry Ljubljana

Chemical Engineering Journal

1385-8947 (ISSN)

Vol. 359 305-320

Ämneskategorier

Oorganisk kemi

Annan kemiteknik

Organisk kemi

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1016/j.cej.2018.11.107

Mer information

Senast uppdaterat

2019-03-04