c) i) Explain the origin of the volcano dependence of the ORR activity on the binding energy of the oxygen intermediate on the catalyst, as in the graph below Activity enhancement, relative to Pt at U = 0.9V (RHE) 100 Overpotential determined by AG Overpotential determined by AG -0.85 PLY Dealloyed PtCu Pt, Ni(111) Cu/Pt(111) near-surface alloys Pt La PU/Pd(111) Pt- Pt/ Au(111)/ 0.0 Pt Co Pt,Fe Pt Ni Pt/Pd/Pd Fe(111) PtSc Pt, Ti 0.2 Pt/Ir(111) -0.80 -0.75 to be negative in free energy U required for all reaction steps AGHO--AG ev Taken from Stephens, Ifan & Bandarenka, Aliaksandr & Gronbjerg, Ulrik & Rossmeisl, Jan & Chorkendorff, Ib. (2012). Understanding the electrocatalysis of oxygen reduction on platinum and its alloys. Energy & Environmental Science. 5. 10.1039/C2EE03590A. ii) If the activity is instead plotted as a function of the binding energy of OH would one obtain the same volcano shape? Justify your answer. [4 Marks] [5 Marks]