Study of acid-base interactions between some metallic oxides and model organic molecules

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 1997-06, Vol.125 (2), p.155-161
• Main Authors: Hamieh, Tayssir, Nardin, Michel, Rageul-Lescouët, Murielle, Haïdara, Hamidou, Schultz, Jacques
• Format: Article
• Language: English
• Subjects: Acid-base interactions; Adsorbents; Chemistry; Donor and acceptor numbers; Exact sciences and technology; General and physical chemistry; IGC; Surface physical chemistry
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/S0927-7757(96)03855-1

Inverse gas chromatography technique at infinite dilution was used to calculate the acidic and basic surface characteristics of three oxides (Monogal, MgO and ZnO). We determined the specific interactions between them and model organic molecules and showed the amphoteric feature of such oxides. It was observed that MgO is more basic than the others. We also proved that the usual relation giving the specific enthalpy of adsorption (Δ H sp) of a polar molecule adsorbed on a solid: (−Δ H sp)=( K ADN+ K DAN) was not correct. We proposed a new relationship by adding a third parameter K reflecting the amphoteric character of the solid according to: (−ΔHsp)= K ADN+ K DAN− KANDN We proved that our model gives the best results relatively to those obtained by the classical equation. Another relationship was also proposed: (−Δ Hsp)= w( K ADN+ K DAN) where w is the weighing factor of the exchanging interactions between adsorbed molecule and solid substrate.