In situ heating STEM images showing the spacial evolution
of Pt
sites at the bulk (a–d) and edge (e–h) in a sample with
10 wt% Pt on PANI with increasing temperatures (RT, 350 °C, 500
°C, and 800 °C) under vacuum. (i–k) Temperature-dependent
XPS data of 1 wt% Pt-PANI under vacuum to show how the bonding environment
of Pt evolves during pyrolysis. Pt 4f spectra (i), N 1s spectra (j),
and Cl 2p spectra (k). (l) XANES of the trapped Pt-SSC synthesized
by pyrolysis, compared with the Pt TPP complex and Pt foil. The inset
is a schematic of the trapped Pt-SSC structure; black for carbon,
blue for N, and gray for Pt.