Wasteomics ⇒ a workflow to analyze complex reaction environments, waste, and realistic feeds conversions



Problem statement

In most heterogeneous catalytic processes, the reactive environment contains a mixture of reactants, intermediates, and products, and some adsorbed-trapped on the catalytic surface and elsewhere. Thus, most reacting environments in catalysis are complex, involve several phases (multiphase), and comprise unstable species or are challenging to analyze. To make things worse, some of these species have (auto-)catalytic or deactivating nature on the kinetics of the surrounding ones.

A typical practice in catalysis is using model molecules or surrogates to deepen into the mechanistic pathways, microkinetics, spectroscopy, etc. Conversely, analytical techniques keep evolving, becoming more precise but always targeting a specific fraction or type of species. That is to say, there is only one technique that solves all.

We aim to bridge the fundamental research performed in our group and outside using model molecules with a powerful analytical multi-technique approach to analyze the entire reaction media. The -omics fields inspire us to reflect on the collective characterization and quantification of pools of molecules that translate into the structure, function, and dynamics involved. We apply our approach to hydrocarbon transformations and green-sustainable feedstock (i.e., waste plastics, sewage sludge, biomass, algae, and seaweed). We develop multi-technique analytical protocols for the complete chemical molecular-level description of complex mixtures.

Goals

  • Analytical workflow ⇒ multi-analytical technique integration
  • Wasteometrics I ⇒ quantitative- and molecular-level analysis
  • Wasteometrics II ⇒ data mining and processing
  • Wasteomics ⇒ reaction networks and kinetic modeling

Related People

Related Publications

Direct analysis at temporal and molecular level of deactivating coke species formed on zeolite catalysts with diverse pore topologies

by Hita, Mohamed, Yerrayya, Zambrano, Zhang, Ramirez, Castaño
Catal. Sci. Technol. Year: 2023 DOI: https://doi.org/10.1039/D2CY01850K

Abstract

he mechanistic understanding of coke formation on zeolites is elusive, given the limitations for the extraction and analysis of coke species. Here, we analyze the evolution of deactivating coke species over time on the surface of Ni/ZSM-5, β and Y zeolites during ethylene oligomerization, which is a representative coke-forming reaction. We present a method that directly analyzes the coke species using high-resolution mass spectrometry on the used catalysts and their isolated soluble and insoluble coke fractions (indirect analysis). Along with other techniques, we report a full-picture temporal evolution of coke and its fractions at the molecular level to establish a correlation between the dominant reaction mechanisms, the location of coke within the catalyst structure, and the observed performance of the catalysts. Ab initio calculations are performed to understand the preferable location of coke. We delve deep into the peculiar deactivation mechanism of ZSM-5 zeolite (MFI structure), which shows two less intuitive parallel deactivation pathways.

Keywords

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