Surface Functionalised Liquid Metals for Catalysis and Green Fuel Synthesis

Liquid metals (LMs) and their alloys, with their inherent fluidity and unique electrohydrodynamic properties, have emerged as promising catalysts for energy conversion and chemical synthesis. Unlike traditional solid catalysts, LMs exhibit self-healing surfaces, tuneable surface tension, and the ability to dissolve metals in low oxidation states, reducing catalyst deactivation and enhancing reaction efficiency. However, their high surface tension poses challenges in scaling catalytic reactions and optimizing interfacial interactions. This thesis investigates new avenues to alter the surface characteristics of LM and utilize their catalytic activity. To begin with, systematic designs of LM-based electrocatalysis electrodes are investigated with a focus on LM-electrolyte maximization for improved catalytic activity. Thus, a scalable system for the creation of microdroplets of liquid metals is established through electrohydrodynamic modulation. It is a method involving the use of electric potentials, enabling precise control over the size of liquid metal droplets while keeping the energy consumption low. The examination of oxide layer modulation reveals its significant influence on the tuning of LM surface tension, particularly in relation to droplet formation and stability. Moreover, the catalytic potential of LM micro- and nano-droplets is examined, with an emphasis on improving the efficiency of the oxygen reduction reaction (ORR). Additionally, this work introduces an on-demand hydrogen production system, where trace amounts of platinum activate gallium-based alloys to facilitate rapid hydrogen evolution. This methodology provides a sustainable and energy-conserving pathway for hydrogen production while simultaneously producing 2D nanoporous platinum electrocatalysts characterized by exceptional ORR activity. This thesis enhances the comprehension of LM catalysis through the integration of experimental, theoretical, and computational insights, offering scalable solutions for electrocatalytic applications. The results of this research significantly advance the overarching progress in sustainable energy technologies and liquid metal-based reaction systems.<p></p>