Oxidation of carbon nanoparticles (NPs) at high temperatures is relevant to many applications of carbon nano-materials, but there are also interesting fundamental questions relating reactivity to NP surface structure, which can vary dramatically for different carbon materials (graphitic, diamond, fullerene, etc.). Even for a particular type of carbon NP, there can be large NP-to-NP variations in the number and types of exposed surface sites, strongly affecting the rates of processes such as sublimation or oxidation. Finally, even for a single NP, the surface structure may evolve during reaction, resulting in large rate variations. To enable study of these effects, we have developed an approach to measuring surface reaction kinetics for individual NPs, held in an electrodynamic trap. For example, we previously found that sublimation of graphitic NPs at temperatures (TNP) > 1700 K was substantially faster than the rates for bulk graphite, varied by up to an order of magnitude from NP-to-NP, and slowed significantly over time, correlated with increases in optical emissivity. This behavior was attributed to the NPs initially having large, but highly variable numbers of undercoordinated surface sites, and that preferential sublimation at such sites reduces the numbers of such sites over time, reducing the rates, and modifying the optical properties. We also reported a study of O2 oxidation of graphitic NPs. Etching rates peaked in the 1200 -1500 K range, dropping at higher TNP. Etching rates varied substantially from NP-to-NP and fluctuated over time for individual NPs. Both effects were attributed to variations in the numbers of under-coordinated reactive sites on the NP surfaces, which evolved as the NPs etched. Surprisingly, it was also found that graphitic NPs eventually evolved to be essentially inert to O2 in the 1200 to 1900 K range, implying that the number of exposed reactive sites dropped to near zero. It was speculated that his evolution to O2 inertness resulted from a transformation of at least the surface layer, to "nano-onion" (multi-wall fullerene) structure.