The selectivity between O2 and Cl2 in the chlor-alkali and chlorate processes Theoretical and experimental studies
by
Rasmus Karlsson(Applied Electrochemistry, KTH)
→
Europe/Stockholm
FA31
FA31
Description
Chlorine and sodium chlorate are important bulk chemicals, with a yearly
production of about 70Mtons and 3Mtons, respectively. They are both produced by
electrolysis of NaCl solutions using electrocatalysts consisting of mixed Ru-Ti
oxides. The cost of electricity is, in both cases, the main production cost.
However, the energy efficiency is limited by the formation of oxygen gas. My
work is focused on understanding why and how oxygen forms in these processes,
to find ways of improving the energy efficiency. In this talk, I will discuss
our recent theoretical and experimental work exploring this issue. The
theoretical study has focused on the electrocatalytic properties of mixed Ru-Ti
oxides, and through first-principles calculations we find that the selectivity
between chlorine and oxygen formation is related to activation of Ti by Ru. The
experimental study has focused on understanding how an important intermediate
in the chlorate process is decomposed homogeneously and heterogeneously. We
find that oxygen and chlorate formation occurs through a shared reaction
mechanism and that Co- and Ir-compounds catalyze the decomposition of the
intermediate.