Abiotic Transformation at the Solid–Liquid Interface - Contaminant Geochemistry - page 369

Table 14.1 Selected examples of reactions catalyzed by clay surfaces (Wolfe et al. 1990 )

Substrate Reaction Type of clay Remarks

Ethyl acetate Hydrolysis Acid clays -

Sucrose Inversion Acid clays -

Alcohols, alkene Ester formation Al-montmorillonite -

Organophosphate esters Hydrolysis Cu- and Mg-montmorillonite,

Cu-beidellite Cu-nontronite

Cu-mont. better catalyst than other
Cu-clays or Mg-mont.

Organophosphate esters Hydrolysis and

rearrangement

Na-, Ca-, and Al-kaolinites
and bentonites

Room and other temperatures.
No liquid phase

Phosmet Hydrolysis Homoinic montmorillonite In suspension

Ronnel Hydrolysis and

rearrangement

Acidified bentonite; dominant
exchangeable cations: H, Ca,
Mg, Al, Fe(III)

Al-catalyzed suggested reaction

s-Triazines Hydrolysis Montmorillonitic clay Cl-analog degrades faster than

methoxy
or methoxythio compounds

Atrazine Hydroxylation H-montmorillonite -

Atrazine Hydrolysis Al- and H-montmorillonite; montmorillonitic

soil clay

Ca- and Cu-clays much weaker
catalysts

1-(4-methoxy phenyl)-2, 3-epoxy
propane

Hydrolysis Homoionic montmorillonites; Na-kaolinite -

DDT Transformation to DDE Homoionic clays Na-bentonite is a better catalyst than

H-bentonite

Urea Ammonification Cu-montmorillonite Air-dried clay at 20 C

Aromatic amines Redox Clays (review) In the presence of metal ions that are

good redox agents

3, 3 0 ,5,5 0 Tetra methyl benzidine Redox Hectorite O 2 oxidizing agent

Pyridine derivatives, olefines, dienes Oligomerization Clays (review) -

Glycine Oligomerization Na-kaolinite, Na-bentonite -