These fits revealed internal magnetic fields of ~5.4 T for the 0.1 wt% and 0.5 wt% samples and a larger field of 8.2 T for the 1 wt% sample (Figure ). These results qualitatively match the catalytic and physiochemical characterization where the two dilute samples are expected to have similar, dispersed sites and the 1 wt% sample should have distinct Ni aggregate-like behavior. As metallic Ni is expected to have internal fields of ~7-8 T and NiO of ~10 T , the spectra and fitted field of 8.2 T for the 1 wt% sample is consistent with the existence of metallic Ni particles with oxide shells. The smaller value of 5.4 T for the 0.1 wt% and 0.5 wt% is indicative of a distinct chemical environment and likely arises from the bonding configuration in the NiNx ligand field.