Titanium based hollow fibre electrodes: fabrication, modification and application

The conversion of electrical energy into chemical bonds, offering similar mobility and flexibility to fossil fuels, has gained much traction over the recent years. The concept of an electrocatalytic refinery (e-refinery) includes a multitude of electrocatalytic processes that convert renewable feedstocks to transportable fuels, commodity chemicals, and specialty chemicals, all driven by renewable electricity. Various industrial scale electrochemical processes are already in use, however the utilization of the gaseous abundant feedstocks (N2, CO2 and CH4) warrants investigation into new electrode systems that remedy the mass transport limitations involved.
One of such novel systems, is based on the use of hollow fibre electrodes (HFEs), which have been primarily investigated as electrode materials for electrochemical CO2 reduction, suggesting significant application prospects. Within the HFE concept an intense three phase contact along the entire electrode is established by purging a reactive gas through the porous electrode wall. This allows for ample reactant to reach the active sites, as well as fast product removal. While this type of electrodes performs remarkably well, a definition of their operation parameters remains elusive.
The work presented in this dissertation provides insights into relevant performance indicators and operational parameters for the HFE concept. The synthesis, operation, modification and application of Ti based HFEs is discussed in several chapters.
The thesis is concluded by assessment of the future perspectives of hollow fibres in electrochemical processes, and which developments are still required to bring the technology to practical application.