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Stable catalyst design for the activation of methane to syngas, hydrogen, and chemicals


    Problem Statement

    Methane and light alkanes are species with relatively poor economic interest. Our goal is to activate C–H σ-bond to produce hydrogen, olefins, carbon monoxide, and carbon nanofibers, following different process strategies such as oxidative coupling (for olefins), CO2 dry reforming (for syngas), cracking or catalytic decomposition (for hydrogen-free of COx and sequestrated carbon nanotubes/nanofibers), cracking/co-cracking with CO or methanol. We work on developing, synthesizing, characterizing, and testing innovative catalysts with a twist of reaction engineering concepts, with a focus on multi-scale implications.

    We delve into the mechanistic insights into a series of in-house-synthesized metal-supported heterogeneous catalysts by combining them with dynamic reactors and ab initio calculations. We explore catalysts with extended lifetimes, enhanced activity, selectivity, and heat transfer. These catalysts are based on alloys-intermetallics, high entropy alloys, exsolved perovskites, and SiC, among others.

    We investigate novel reactor designs based on forced-dynamic, operando, and fluidized-bed reactors to amplify kinetic information and improve selectivity.

    CHA2023

    Goals

    • Develop a microkinetic-based modeling framework to analyze the catalyst performance
    • Scale the technical catalyst for its application in demanding exothermic (oxidative coupling of methane using SiC and spray drying) or fluidized-bed (catalytic decomposition of methane) conditions
    • Develop new catalytic concepts based on Ni-alloys (Ni-Fe, -Co, -Zn…)
    • Improve the catalyst structure-function correlations using in-situ, operando, and dynamic techniques and reactors

    Related People

    Related Publications

    Engineering the TiOx Overlayer on Ni Catalyst to Balance Conversion and Stability for Methane Dry-CO2 Reforming

    by Bai, Yao, Cheng, Mohamed, Telalovic, Melinte, Emwas, Gascon
    ACS Sustainable Chem. Eng. Year: 2024 DOI: https://doi.org/10.1021/acssuschemeng.3c07051

    Abstract

    Ni-supported catalyst is a viable system to convert methane and carbon dioxide into syngas through methane dry reforming, with the main drawbacks of its fast deactivation being sintering and coking. Here, we developed methods to engineer a TiOx overlayer on Ni/TiO2 catalysts to shield the catalyst against sintering and coking while preserving the Ni accessibility and, thus, conversion. These methods involved altering TiO2crystal phases, pretreatment, and reaction conditions in the reforming stage. Through characterization, testing, and operando spectroscopy, we found that the TiOx overlayer with incomplete Ni coverage maintained a balanced conversion and stability by quenching the sintering and coking. Conversely, thick or nonexistent overlayers led to lower conversions or faster deactivation. The formation of TiOx overlayer increased the CO2activation capacity and oxygen mobility and protected Ni from sintering by its shield function. At the same time, the reaction pathways remained unchanged despite the TiOx overlayer with different morphologies.

    Keywords

    CHA HCE