Sensor element, gas sensor, and sensor element manufacturing method

A sensor element comprising:

• an oxygen-ion conductive solid electrolyte body, a detection electrode which is provided on one surface of the solid electrolyte body and comes into contact with a gas to be measured, and a reference electrode which is provided on the other surface of the solid electrolyte body and comes into contact with a reference gas,
• the sensor element being characterized by further comprising a catalyst layer which covers the detection electrode, the catalyst layer including a porous carrier formed of ceramic particles, and catalyst particles supported on the carrier and formed of one or more noble metals selected from a group consisting of Pt, Pd, Rh, and Au,
• wherein the carrier includes oxide particles bonded to portions of surfaces of the ceramic particles, the oxide particles having a composition different from that of the ceramic particles, being smaller than the ceramic particles in terms of circle-equivalent diameter in a cross-sectional image, and being formed of zirconia, alumina, or lanthana, and
• the catalyst particles are supported on at least either of surfaces of the oxide particles and the surfaces of the ceramic particles.