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This paper combines the processing of composite synchronizer ring and carbon fiber cloth pre-preg process to study the friction mechanism after adding filler in carbon fiber cloth of composite synchronizer ring, so as to improve the friction and wear performance of composite synchronizer ring. In order to increase the friction factor and thermal stability of composite synchronizer ring friction material two ways as an entry point, select the friction reducing filler in the good thermal conductivity of copper powder and friction increasing filler in the barite as the experimental filler in this paper. The results show that the friction temperature of the composite synchronizer ring without filler is higher and the wear is bigger, the composite synchronizer ring with barite as the filler is second, and the composite synchronizer ring with copper powder as the filler has the best effect of temperature reduction and wear reduction. In the shift force of 400 N, speed difference of 350 r/min, experimental time of 250 min conditions, adding copper powder to reduce the wear volume of about 10%, the friction coefficient is more stable average value decreased by about 0.02, only reduced by about 5%, which is better than the barite as a filler of 0.045; and from the surface quality of the composite synchronizer ring with copper powder as a filler the surface texture is clear. Still has a good oil storage and drainage capacity, can effectively improve the composite synchronizer ring wear resistance and service life. Barite as filler composite synchronizer ring initial friction coefficient is slightly higher, but the coefficient of friction decreased by about 20%, the composite synchronizer ring scratches and local carbon fiber shedding phenomenon, resulting in irreversible performance degradation.

Electrocatalytic reduction of CO2is important for mitigating global warming and energy crisis, and the key to an economical and promising CO2conversion technology lies in the development of catalysts with high catalytic activity. Here, we report a N-doped carbon-based bimetallic single-atom catalyst (Fe/Mn–N–C) to improve the selectivity of electrocatalytic reduction of CO2products by combining with highly active iron-manganese bimetals. At the carbonation temperature of 800 °C and the Fe/Mn mass ratio of 1:2 in the precursor, the catalyst Fe/Mn–N–C was able to achieve a Faraday efficiency (FE) of 94% for CO in 0.1 M KHCO3electrolyte at an overpotential of −0.5 V (RHE), which was much higher than that of the Fe–N–C (40%), Mn–N–C (25%), and N–C (25%). And after 12 h of continuous catalysis, the FECO was still maintained at more than 80%, demonstrating the good stability of the Fe/Mn–N–C. X-ray absorption spectroscopy (XAS) results confirmed the diatomic dispersed MxNyactive centers embedded in the exposed substrate of the carbon surface and their dispersion was confirmed by high angle angular dark field-scanning transmission electron microscopy (HAADF-STEM) with atomic resolution. Density functional theory (DFT) calculations showed that the reaction potential for COOH* formation and CO desorption was reduced by the synergistic effect of the adjacent Fe–Mn centers. This work provides a great possibility for the preparation of bimetallic single atom catalysts for efficient catalytic conversion of CO2.