"The effect of the framework Al content and synthesis procedure on the number of framework Al atoms located on the surface of (Al)MCM-41 channels and the distribution of the Al atoms between single Al atoms and various Al-O-(Si-O)1,2-Al species was investigated. The total number of accessible framework Al atoms on the channel surface was obtained from the ion exchange capacity for Na+ ions and pyridine adsorption. The number of Al pairs on the surface and their distribution between different local arrangements of the channel surface was estimated using Vis spectroscopy of Co2+ ions. At low framework Al contents, Al atoms occupy only accessible T sites on the surface of the channel walls. In aluminium-rich (Al)MCM-41, a significant part of Al atoms is incorporated inside the channel walls and these Al atoms do not form cationic sites. Al atoms on the wall surface preferentially form Al-O-(Si-O)1,2-Al sequences, enabling siting of divalent cations."@en . . "597812" . . "\u017Dilkov\u00E1, Nad\u011B\u017Eda" . "Kotrla, Josef" . . "Collection of Czechoslovak Chemical Communications" . . . "0010-0765" . . . . "molecular sieves; mesoporous materials; Vis spectroscopy"@en . . "10" . "(Al)MCM-41 Molecular Sieves. Aluminium Distribution, Uniformity and Structure of Inner Surface."@en . "21"^^ . . "RIV/61388955:_____/03:54030154!RIV/2004/AV0/A54004/N" . "RIV/61388955:_____/03:54030154" . . . "CZ - \u010Cesk\u00E1 republika" . . "4"^^ . "1998;2018" . "68" . . . . "0"^^ . . . "4"^^ . "(Al)MCM-41 Molecular Sieves. Aluminium Distribution, Uniformity and Structure of Inner Surface." . . "0"^^ . "[8411EA2468BC]" . . "The effect of the framework Al content and synthesis procedure on the number of framework Al atoms located on the surface of (Al)MCM-41 channels and the distribution of the Al atoms between single Al atoms and various Al-O-(Si-O)1,2-Al species was investigated. The total number of accessible framework Al atoms on the channel surface was obtained from the ion exchange capacity for Na+ ions and pyridine adsorption. The number of Al pairs on the surface and their distribution between different local arrangements of the channel surface was estimated using Vis spectroscopy of Co2+ ions. At low framework Al contents, Al atoms occupy only accessible T sites on the surface of the channel walls. In aluminium-rich (Al)MCM-41, a significant part of Al atoms is incorporated inside the channel walls and these Al atoms do not form cationic sites. Al atoms on the wall surface preferentially form Al-O-(Si-O)1,2-Al sequences, enabling siting of divalent cations." . "(Al)MCM-41 Molecular Sieves. Aluminium Distribution, Uniformity and Structure of Inner Surface."@en . "D\u011Bde\u010Dek, Ji\u0159\u00ED" . "(Al)MCM-41 Molecular Sieves. Aluminium Distribution, Uniformity and Structure of Inner Surface." . . . "P(GA104/02/0571), P(IAA4040001), P(IBS4040017), Z(AV0Z4040901)" . "\u010Cejka, Ji\u0159\u00ED" .