Improvement of desulfurization properties of -conjugated carbon materials by phosphorus doping

Shimoyama, Iwao   ; Baba, Yuji  

Thiophene adsorption property on graphite was studied to clarify influence of N and P dopings for the application of adsorptive desulfurization of carbon alloys. An Ar -irradiated sample was also prepare to compare the influence of radiation damage, and all the samples were exposed to thiophene gas with saturated condition after ion beam doping. Thiophene coverages were estimated from XPS, and thiophene adsorption abilities obtained from the coverage and dopant density showed P-doped sample had larger value than N-doped sample by about 20 times. And room temperature doping showed larger adsorption ability than high-temperature doping for P-doped samples by about 10 times. We have clarified that planar P sites were preferentially formed by high-temperature doping and curved P sites were preferentially formed by room-temperature doping. This suggests that curved P sites have higher adsorption property than planar P sites. We compared these experimental results with theoretical results of minimum energy path analysis using molecular orbital calculations, and confirmed influence of P doping for the improvement of thiophene adsorption property.