Microwave Alloying of Cyanogels & Electrochemical Simulation of [MnBpyCO3py] for Carbon Dioxide Reduction

Abstract

Metal alloys and complexes are known to electrochemically reduce carbon dioxide to less harmful substances, a process which has garnered more interest now than ever before given the serious consequences of rising CO\(_{2}\) levels in the atmosphere. Cyanide-bridged metal networks made from a combination of cyanometalates and chlorometalates - known as cyanogels - are known to produce homogeneous alloys under microwave irradiation, facilitating a rapid, low-energy method of electrocatalyst fabrication. This two-part thesis explores the optimal synthesis procedure and electrocatalytic potential of Ni-embedded Pd/Pd cyanogel-based alloys and also determines the redox potential of [Mn(bipyridyl)(CO)\(_{3}\)py], a known electrocatalyst for CO\(_{2}\) reduction, via computations using DigiElch simulation software. 60 mM PdCl\(_{4}^{2-}\) dissolved in 0.25 M KCl solution combined with 60 mM Pd(CN)\(_{4}^{2-}\) solution in a 2:1 ratio under chilled conditions resulted in the most reproducibly stable gel which, following 0.1 M NiCl\(_{2}\) soaking, was conducive to microwave processing into PdNi alloys of knob-like morphology. Cyclic voltammetry simulations of [Mn(bipyridyl)(CO)\(_{3}\)py] determined a value of -1.76 V vs. Ag/AgCl for CO\(_{2}\) reduction with an overpotential likely to be lower than in related systems. The reliable method of Ni-Pd/Pd alloy synthesis will enable more detailed electrochemical characterization of CO\(_{2}\) reduction on this system, and the promising redox potential and otherwise inaccessible mechanistic properties of [Mn(bipyridyl)(CO)\(_{3}\)py] suggested by computational derivation encourages development of this complex into an even better electrocatalyst.