Exploring induction heating catalysis with nano-indium on silica: From room-temperature to thermal synthesis of 1,3-dioxolane as a new sustainable fertilizer enhancer

Abstract

In this study, we present, for the first time, an indium nanoparticle system deposited on SiO₂ (In/SiO₂) as a highly efficient catalyst synthesizing of 1,3-dioxolanes. We also report, for the first time, the incorporation of the In/SiO₂ system into the Induction Heating Catalysis (IHC) platform. This innovative approach eliminates the need for strong acids or organic co-solvents. IHC is a relatively new method. We need to test its applicability. In our previous IHC experiments in liquid phase, we loaded the catalyst on the IHC active ferromagnetic material, e.g., Ni wool. Now, we show in numerous experiments with blank samples that even at the minute catalytic amount, we are observing the IHC effect through increased reactant conversion. The In/SiO₂ catalyst demonstrated sufficient activity even at room temperature. The reaction mechanism, indicated by TOF-SIMS analysis, reveals a dual synergistic activation between indium and silica, facilitating the acetalization. The kinetic analysis identified a second-order model as the best fit, with the reaction occurring in the kinetic region. The catalyst with In NPs deposited on granulated silica limits leaching and enables the production of high-purity products. We also explored the Pervap™ 4100HF polymer membrane to remove water from post-reaction mixtures, favorably altering the reaction equilibrium. Additionally, cyclic ketals were tested as fertilizer adjuvants to improve maize yields, showing the potential to reduce fertilizer usage by up to 50 % without compromising crop productivity. This class of adjuvants may help for sustainable fertilizer management and reduce the anthropogenic carbon footprint in accordance with current and future legal regulations (United Nations - Agenda 2030).