Robert Raja

Vibrational techniques such as infrared spectroscopy and inelastic neutron scattering offer complementary information into reagent–catalyst interactions. While infrared spectroscopy emphasizes modes with strong changes in dipole moment, inelastic neutron scattering highlights vibrational modes, which displace hydrogen atoms, independent of the effect on dipole moment. In this study, findings from these techniques were combined to probe the interactions of ethanol with two distinct silicon-doped aluminophosphate frameworks, enabling direct comparisons on their reactivity and catalytic mechanisms for ethanol dehydration. By mimicking actual reaction conditions and correlating with reactivity data, these in situ and operando measurements highlighted the different behaviors of the two catalysts. Furthermore, detailed computational calculations supported the assignment of spectral features, providing a detailed understanding of ethanol dehydration over these materials.

Membrane-separated chlorine flow reactors provide a route to on-demand free available chlorine (FAC) generation, but their performance depends on coupled transport, electrochemistry, and non-ideal electrolyte thermodynamics. This study develops a local Pitzer-coupled CFD framework for chlorine electrosynthesis in a single-pass sodium chloride (NaCl) flow cell. The resolved composition field is used to evaluate ionic activity coefficients and water activity, which are propagated consistently through chlorine hydrolysis, activity-based electrode equilibrium potentials, and the scalar conductivity closure governing electrolyte-potential gradients and migration. The computational model combines, Nernst–Planck species transport, electrolyte charge conservation, Butler–Volmer kinetics, and activity-corrected hydrolysis relaxation. Model assessment was performed over flow-rate, current-density, and NaCl-concentration sweeps using directly measured outlet free active chlorine (FAC) and two-electrode full-cell voltage as the primary observables. Across nine operating cases, the mean error was ±0.067 mM for FAC and ±0.080 V for full-cell voltage, with corresponding RMSE values of 0.105 mM and 0.094 V. The largest percentage deviations occurred at low absolute concentrations or at boundary operating cases, so percentage error was used as a secondary descriptor rather than the sole measure of agreement. Resolved fields showed that flow rate alters oxidant retention and outlet sampling, current densityamplifies chlorine production, acidity, and migration, and NaCl concentration changes both conductivity and the chlorine-hypochlorous acid partitioning. Increasing salt concentration reduced the electrical burden but shifted the product stream towards dissolved chlorine, demonstrating a voltage–speciation trade-off. The framework therefore provides an activity-corrected basis for interpreting and designing chlorine flow cells within a supported single-phase operating window

Multiscale experimental and computational investigations have provided valuable information for scaling up of methanol dehydration to dimethyl ether using solid acid catalysts.

Microporous solid acid catalysts are widely used in industrial hydrocarbon transformations in both the fuels and petrochemical industries. The specific choice of microporous framework often dictates the acidic properties of the system, such as acid site strength and concentration. In this work we have explored the influence of acid site concentration on butane isomerisation activity and the mechanistic pathway by controlling the quantity of magnesium doped into an aluminophosphate, keeping the acid site strength and framework topology constant. By combining experimental kinetic studies, and theoretical mechanistic studies, we conclude that isobutane formation, from n-butane, predominantly proceeds through a bimolecular pathway. Specifically, the activity of the system is strongly linked to the presence of alkenes, and herein the precise mechanistic roles of the alkenes are explored.

A novel multidimensional analytical tool was used to vindicate and improve the performance of bifunctional catalysts used for the one-pot conversion of CO2 to sustainable fuels.

Carbon nanotemplates are used to create hierarchical silicoaluminophosphate materials, with superior catalytic performance to microporous materials. Their hierarchical nature is probed with in-depth microscopy and small-angle neutron scattering.

A highly selective bifunctional catalyst for the one-pot conversion of CO₂ to DME using CuZnO nanoparticles located on SAPO-34 crystals.

The direct/reductive amination of carbohydrate-based furoin and furil with NH₃/H₂ was investigated to access amine derivatives.