General discussion by Masson, A, Howie, A, Thomas, J, Buffat, P, Joyner, R, Zamaraev, K, Gallezot, P, Rao, C, Benfield, R, Henglein, A, Matijević, E, Bradshaw, A, Edwards, P, Bradley, J, Wrona, P, Roberts, M, Miessner, H, Mile, B, Dye, J, Gauntlett, J, Kuroda, H, Creighton, J, Greenslade, D, Boudart, M, Couves, J