Dissolved gas analysis in oil is one of the most effective methods for fault diagnosis oil-immersed transformers. Therefore

detection of characteristic gases in oil is essential to maintain the power transformer normal operation. In this paper

CeO2-based gas-sensitive materials were prepared using a one-step hydrothermal synthesis

and the successful preparation of the materials was verified by XRD

SEM and XPS characterization techniques. Based on the established gas-sensitive platform

the temperature-response characteristics

mole fraction-response characteristics

repeatability

response-recovery characteristics and selectivity of the Cu-CeO2 sensor for C2H4 were tested. It is found that the optimal operating temperature of Cu-CeO2 for C2H4 is 180 ℃

and the response value of 100×10-6 mole fraction C2H4 is 66%. The response time and recovery time are 18 s and 15 s

respectively. The sensor exhibits excellent interference resistance against C2H2

C2H6

H2

CH4

CO2

and CO gases. Furthermore

based on the first-principal calculation

the gas-sensing mechanism of the Cu-CeO2 sensor for the oil-immersed characteristic gases was analyzed by calculating the adsorption parameters

density of states

and electron density of the adsorption system. The results indicate that the Cu-CeO2 crystal surface exhibits strong chemical adsorption only for C₂H₄

with an adsorption energy of -1.488 eV

and the calculated results are consistent with the findings from macroscopic gas-sensing experiments. Thus

the gas-sensing performance analysis and theoretical calculations in this paper provide a theoretical basis and experimental support for the development of low-power

high-sensitivity

and fast-response C2H4 sensor for the characteristic gas in oil detection.