Gas pressure on the reaction kinetics for synthesizing graphite

To further examine the effect of CO2 concentration and gas pressure on the reaction kinetics for synthesizing graphite, inert argon was first introduced into the 35 bar CO2–LiAlH4 reactor until the gas pressure of 75 bar was reached. During heating, CO2 reacted with LiAlH4 as sudden changes in temperatures and gas pressure were detected. The as-synthesized carbon exhibits stronger XRD peaks of graphite and weaker XRD peaks of amorphous carbon than the carbon synthesized under 35 bar CO2, further supporting that more graphite is produced in the carbon synthesized under higher gaseous back pressure. This can also be concluded from the Raman spectrum. The intensity ratios of the G band to the D band and the 2D band to the D band are calculated to be 1.37 and 0.40, respectively, greater than 1.01 and 0.09 of the carbon synthesized under 35 bar CO2. When the CO2 pressure increases to the value, the intensity ratios of the G band to the D band and the 2D band to the D band increase to as high as 3.9 and 1.8, respectively, for the graphite submicroflakes. It can be concluded that the kinetic barriers of the reaction for synthesizing graphite decrease with the gaseous back pressure. In addition, CO2 concentration has little effect on the kinetic barriers of the reaction for synthesizing graphite in contrast with gaseous back pressure. Compared to graphite submicroflakes, it can be concluded that the content of graphite in as-synthesized carbon decreases with the CO2 pressure applied in the synthesis process resulting from the reaction kinetics of synthesizing graphite related to CO2 pressure. If you are looking for high quality, high purity, and cost-effective graphite or require the latest price, please email contact mis-asia.

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