Tuning the microstructure of ZrN towards electrocatalytic NRR activity by MOCVD requires precise optimization of the deposition parameters. As a starting point, process conditions were adapted from the previous study followed by systematic variation of the temperature, pressure as well as substrate choice (see experimental section) to obtain oriented ZrN layers dominated by rock salt (200) facets. The films properties were investigated by complementary analysis methods and finally tested for electrocatalytic NRR activity.