Rapid kinetic evaluation of inorganic-perovskite-catalysed redox conversion of p-nitrophenol and morin aided by an opentrons robotic system

Herein, the rapid kinetic evaluation of p-nitrophenol (p-NP) reduction and oxidation of Morin using inorganic perovskites as catalysts is reported. The perovskites were synthesised using the hard template method with KIT-6 as a template resulting in high surface areas (~ 687m²/g). The kinetic analysis was done with the aid of an open-source Opentrons liquid handling robot, a microplate reader with 96 wells. In four hours, twelve variations with three replicates were conducted for four different catalysts, a time-efficient and reproducible approach. The reduction of p-nitrophenol and oxidation of Morin followed the pseudo-first-order reaction kinetics. The best catalyst for reducing p-nitrophenol was LaSnO₃ with an observed rate constant of 3.5 × 10^–2 s⁻¹, and for the oxidation of Morin the best catalyst was LaFeO₃ with 3.9 × 10^–3 s⁻¹. We postulate that the catalytic activities were dependent on the surface areas, oxidising strengths, and reducibility of the B cation of the perovskite's ABO₃ crystal structure, determining their binding affinity to the reducing agent. Furthermore, the as-synthesised catalysts showed good stability and reusability of up to four cycles. Graphical abstract: [Figure not available: see fulltext.].