Microkinetics of alcohol reforming for H2 production from a FAIR density functional theory database

Abstract

The large-scale production of hydrogen from biomass under industrial conditions is fundamental for a sustainable future. Here we present a multiscale study of the available reforming technologies based on a density functional theory open database that allows the formulation of linear scaling relationships and microkinetics. The database fulfills the FAIR criteria: findability, accessibility, interoperability and reusability. Moreover, it contains more than 1000 transition states for the decomposition of C2 alcohols on close-packed Cu, Ru, Pd, and Pt surfaces. The microkinetic results for activity, selectivity toward H2, and stability can be directly mapped to experiments, and the catalytic performance is controlled by various types of poisoning. Linear scaling relationships provide valid quantitative results that allow the extrapolation to larger compounds like glycerol. Our database presents a robust roadmap to investigate the complexity of biomass transformations through the use of small fragments as surrogates when investigated under different reaction conditions.

Developments in the Atomistic Modelling of Catalytic Processes for the Production of Platform Chemicals from Biomass

“…As we have explained above, many functional groups are present in different parts of the molecule. In many cases, we have found that the barriers of several parallel paths are comparable, thus they might be active simultaneously . This means that a successful analysis of the reaction network requires the use of microkinetic models so that the molecular insight obtained for all elementary steps can be mapped to experimental data like reaction orders, activation barriers, activity of catalyst, and product selectivity .…”

“…This reduction is very convenient to optimize reaction conditions. However, this approach cannot be used to screen catalytic systems, as the potential catalysts might prefer different reaction paths, e. g ., the reforming of ethanol on Pd and Pt . Another approach is to consider flow reactors to be in quasi‐equilibrium.…”

“…Another approach is to consider flow reactors to be in quasi‐equilibrium. Despite removing the dependence on time, this simplification may yield unphysical results as flow reactors may operate in a pseudostationary state ,. Several simplifications are common during the obtention of the free energies; therefore, the accuracy can be increased with a correct description of the entropy terms .…”

“…Particularly in our group we computed the full set of reactions encompassing the decomposition of all these species on four different metals (Cu, Ru, Pd, and Pt), comprising 75 intermediates and 250 transition states for each metal. This allowed us to unveil the activity of these materials for hydrogen production under four reaction conditions ,. We focused on the direct decomposition to compare our results with surface science data, as well as three emerging technologies: autothermal reforming, steam reforming, and aqueous phase reforming.…”

“…Taking these structures, we considered all the possible decomposition pathways arising from C−H, O−H, C−C, and C−O breakings, as well as the water‐gas shift reaction. The resulting reaction network contains 75 intermediates and 250 transition states ,. Due to its complexity, a genomic notation was developed to label the intermediates and easily account for the different decomposition routes of C 1 and C 2 alcohols on the metals under study.…”