Operando Spectroscopy in Heterogeneous Catalysis

Operando spectroscopy encompasses a suite of analytical techniques applied simultaneously with catalytic reactions under real working conditions, enabling direct correlation between the dynamic structure of a catalyst and its performance. In heterogeneous catalysis, active sites often undergo reversible transformations—oxidation state changes, surface restructuring or interactions with reactants and intermediates—that are invisible in ex situ characterisation. By integrating spectroscopic probes such as X-ray absorption, infrared and diffraction methods with online product analysis, researchers can resolve transient species, quantify kinetic barriers and unravel mechanistic pathways in real time. The advent of high-brightness synchrotron sources, rapid detectors and advanced data-processing algorithms has elevated operando initiatives from qualitative snapshots to multidimensional, time-resolved studies across Ångström to micrometre length scales. This deeper insight underpins the rational design of catalysts for applications ranging from low-temperature emissions control and fuel synthesis to biomass conversion and renewable energy storage. Crucially, operando spectroscopy bridges the gap between fundamental surface science and industrial reactors, driving optimisation of activity, selectivity and stability under conditions of temperature, pressure and complex gas or liquid environments encountered in practical operation.

Research from Nature Portfolio

Time-resolved diffuse reflectance infrared Fourier transform spectroscopy combined with X-ray absorption fine structure and mass spectrometry has revealed a platinum carbonate–mediated mechanism for room-temperature carbon monoxide oxidation over Pt/Al₂O₃. By operating in a periodic reduction–oxidation mode, this approach demonstrated reversible interconversion between metallic platinum nanoparticles and oxidic centres, establishing a low-temperature catalytic cycle that hinges on molecular communication between distinct platinum sites.

A five-dimensional operando tomographic diffraction imaging methodology has been applied to a complex Ni–Pd/CeO₂–ZrO₂/Al₂O₃ catalyst during partial oxidation of methane. This technique integrates three spatial dimensions with scattering and temporal domains to produce Rietveld-analysed maps of lattice parameters, crystallite sizes and phase distributions at sub-micrometre resolution. The study captured the evolution of nickel species and promoter roles, elucidating pathways of catalyst deactivation under reactive atmospheres by linking local structural heterogeneities to macroscopic performance.

Operando Spectroscopy in Heterogeneous Catalysis publication trend

The graph below shows the total number of articles in operando spectroscopy in heterogeneous catalysis across all publications each year (not limited to Nature Index journals).

Technical terms

Operando spectroscopy: Simultaneous acquisition of spectroscopic data and catalytic performance metrics under genuine reaction conditions.

X-ray absorption spectroscopy (XAS): A technique measuring absorption of X-rays by an element to probe electronic structure and local geometry, including XANES and EXAFS regions.

Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS): Infrared method capturing vibrational signatures of surface species on powdered catalysts in situ.

Extended X-ray absorption fine structure (EXAFS): Analysis of oscillatory fine structure beyond the absorption edge to determine interatomic distances and coordination numbers.

Tomographic diffraction imaging: Reconstruction of three-dimensional maps of crystalline phases and strain by rotating the sample under a diffraction beam, extended to include time as an additional dimension.

References

1. Room-temperature carbon monoxide oxidation by oxygen over Pt/Al2O3 mediated by reactive platinum carbonates. Nature Communications (2015).
2. 5D operando tomographic diffraction imaging of a catalyst bed. Nature Communications (2018).
3. In Situ and Operando Spectroscopy: A Powerful Approach Towards Understanding Catalysts. Johnson Matthey Technology Review (2018).
4. Combined spatially resolved operando spectroscopy: New insights into kinetic oscillations of CO oxidation on Pd/γ-Al2O3. Journal of Catalysis (2019).
5. Formation and Functioning of Bimetallic Nanocatalysts: The Power of X‐ray Probes. Angewandte Chemie International Edition (2019).