Time-Resolved Analysis of Isotopic Exchange reveals fast mechanical steps in catalytic oxidation – TRAIE

Operando coupling of Steady-State Isotopic Transient Kinetic Analysis (SSITKA) and Fourier Transform InfraRed (FTIR) spectroscopy has evolved as one of the most powerful combination to investigate reaction mechanisms under real conditions. Information regarding catalytic surfaces, active sites and true intermediate species are necessary to design new catalysts able to achieve higher conversion and selectivity. However, “grey zones” about very fast reaction elementary steps (spillover, molecule flip, deoxygenation) have yet to be revealed. In this project, the innovative combination of SSITKA with time resolved FTIR methodology (ms-µs time scale) will help us to remove scientific barriers to define more detailed heterogeneous catalytic oxidation mechanisms.

In practice, the ultimate scientific and technical barriers to be lifted and the results expected during the TRAIE project are:
(i) The optimization of a new combined SSITKA/Time-resolved IR (rapid and step-scan modes) set-up able to acquire reliable kinetics data and and new insights about the nature of fast elementary steps, active intermediate species and catalyst reactivity.
(ii) The test and validation of the operando SSITKA/Time-resolved IR methodology using model reactants and previous literature results. A particular attention will be paid to the amount of data collected and to develop a proper method of data treatment and interconnection.
(iii) The investigation of the fast elementary steps of CO and CH4 oxidation reactions over Pt and Pd supported on alumina, respectively, using the SSITKA/Time resolved IR newly developed methodology to establish a more relevant surface-site reactivity relationships and thus, fully depict the different routes of the reaction mechanisms.
(iv) The extend of the methodology and result to other relevant catalytic systems using other nature of metallic particles (Rh or Ag), metal-free oxide materials or fully dispersed metallic phase as single atoms. The use of the latter is expected to emphasize the not well-understood differences in the reaction intermediates and/or mechanistic routes from supported large metal nanoparticles.

The TRAIE project tackles an important scientific issue in catalysis in order to obtain significant breakthrough in heterogeneous mechanisms understanding. In our knowledge, the combination of these powerful techniques will be achieved for the first time. Ultimately, the fundamental knowledge acquired during the fulfillment of the TRAIE project goals could be apply to catalyst material selection and/or design able to succeed high selectivity to desired products with low energy cost.

The realization of the 42 month JCJC project will be ensured by a young researcher and the recruitment of a Ph.D. student in UCCS laboratory. The data and results of this project will be disseminated as much as possible in open-access sources for the scientific community and the general public.