Synthesis, studies and fuel cell performance of “core–shell” electrocatalysts for oxygen reduction reaction based on a PtNix carbon nitride “shell” and a pyrolyzed polyketone nanoball “core”

Interplay between morphology and electrochemical performance of “core–shell” electrocatalysts for oxygen reduction reaction based on a PtNix carbon nitride “shell” and a pyrolyzed polyketone nanoball “core”

“…4(b1) and (b2) demonstrate that the average size of the PtNi x alloy NPs is equal to 8.2 AE 2.1 nm and 10.7 AE 3.5 nm for PtNieCN l 600/S500 and PtNieCN l 900/S500, respectively. The morphology of S500 and S700 "core" supports used for the preparation of the PtNieCN l T f /ST p electrocatalysts is consistent with that shown in details elsewhere [28], as follows: (a) both S500 and S700 ST p "core" supports are characterized by a relatively small ). Very small PtNi x alloy NPs are obtained in the electrocatalyst if the Z-IOPE precursor is spread as a thin layer over a conducting "core" support [27].…”

“…The samples are suspended in isopropyl alcohol; a 5 mL drop of the suspension is deposited on a holey carbon film supported on 3 mm copper grid. The chemical composition of the electrocatalysts is determined by ICP-AES and microanalysis as described in our earlier papers [26,28]. The details of the procedure adopted in the preparation of the electrodes to carry out the electrochemical measurements with the CV-TF-RRDE method are reported elsewhere [21,26].…”

“…The electrocatalysts investigated in this work are obtained as described elsewhere [28] using a procedure which involves two main steps: (a) preparation of the ST p "core" supports; and (b) synthesis of the electrocatalysts. The ST p "core" supports are obtained by growing polyketone (PK) fibers on XC-72R carbon nanoparticles; subsequently, the samples are treated with conc.…”

“…In the "coreeshell" morphology, the carbon nitride (CN) "shell" matrix embedding the metal nanoparticles bearing the active sites is supported on a "core" of conducting nanoparticles [26,27]. In this work, innovative "core" supports based on pyrolyzed polyketone nanoballs are used in the preparation of a family of PtNi x alloy "coreeshell" carbon nitride-based electrocatalysts as described elsewhere [28]. These electrocatalysts present a formula PtNieCN l T f /ST p , where PtNieCN l T f refers to the "shell", and ST p denotes the electrolcatalysts' "core".…”

Graphitic Carbon Nitride Materials for Energy Applications

“…Various graphitized carbon support materials with special pore structures have also been explored, such as carbon nanotubes (CNT), nanofibers (CNF), nanohorns (CNH) and nanocoils, all showing promising results, although the costly and complex synthesis methods employed constitute a barrier to their introduction into market (34)(35)(36)(37)(38)(39)(40). The introduction of nitrogen into carbon supports has showed to improve durability, as well as enhancing the intrinsic catalytic activity for both oxygen reduction (ORR) and methanol oxidation (MOR) reactions (41)(42)(43)(44)(45)(46)(47)(48). The N-dopant has been reported to alter the catalyst electronic structure, resulting in a higher binding energy, which may decrease the specific interaction between the Pt nanoparticles and potential poisoning intermediates (49).…”