“…The elevated temperature of exhaust gases and exhaust gas content make potentiometric sensors the most appealing option. In the literature, zirconia and platinum are widely employed as electrolyte and reference electrodes, respectively [10][11][12][13][14][15][16][17]. As working electrodes, different oxides, from simple to more complex oxides [12,[17][18][19][20][21] such as spinels and perovskites, are used for the detection of several elements, e.g., hydrocarbons [10,15,[22][23][24][25][26], CO [19,[27][28][29], and NH 3 [30,31].…”