**4. Conclusions**

From the analysis of the effect of Ti partial substitution by Mn, Fe, Co, or Cu on the NOx storage capacity (NSC) of the BaTi0.8B0.2O3 lean NOx trap (LNT) catalyst, the following conclusions have been obtained:

	- - (i) For the BTCuO\_2 catalyst, the tetragonal structure of the raw perovskite is distorted, a larger amount of oxygen vacancies is generated and Ba2TiO4 and BaCO3 appear as main minority segregated phases, but CuO is also detected.
	- - (ii) For Mn, Fe, and Co, the tetragonal structure changes to cubic, a lower amount of oxygen vacancies are formed and BaCO3 appears as segregated phase in the three catalysts. BTCoO\_2 presents also BaCoO3 and Co3O4 segregated phases due to a lower degree of Co insertion into the framework.

**Author Contributions:** Conceptualization, V.A.-F. and M.-J.I.-G.; Methodology, V.A.-F. and M.-J.I.-G.; Validation, V.A.-F, M.-S.S.-A., and M.-J.I.-G.; Formal analysis, C.A., V.T.-R., V.A.-F, M.-S.S.-A., and M.-J.I.-G.; Investigation, C.A., V.T.-R., V.A.-F.; Resources, M.-S.S.-A. and M.-J.I.-G.; Data curation, V.A.-F., M.-S.S.-A. and M.-J.I.-G.; Writing—original draft preparation, C.A., V.T.-R., and V.A.-F; Writing—review and editing, M.-S.S.-A. and M.-J.I.-G.; Visualization, C.A., V.A.-F., and M.-S.S.-A.; Supervision, V.A.-F. and M.-J.I.-G; Project administration, M.-J.I.-G.; Funding acquisition, M.-S.S.-A. and M.-J.I.-G.

**Funding:** This research was funded by Generalitat Valenciana (PROMETEO/2018/076 and Ph.D. grant ACIF 2017/221), Spanish Government (MINECO Project CTQ2015-64801-R) and EU (FEDER Founding).

**Conflicts of Interest:** The authors declare no conflict of interest.
