Figure 5. ( a ) normalized conversion; ( b ) Ni 2p XPS spectra after isooctane reforming on Ni (red) and on Sn/Ni (blue); ( c ) XRD spectra for post-isooctane Ni and Sn/Ni, and for fresh Ni catalysts, and ( d ) post-reaction STEM micrograph of Ni and Sn/Ni [38].