Pillared products

A quartz-free nontronite sample (6) was expanded by reacting a slurry containing 0.0075 g clay/g water with an excess of ChlorhydrolA pillared product was obtained that after drying at -100 C had a d(OOl) spacing of 19.4A. Calcination in air at 400 C/10h reduced the d(OOl) value to 16.9A the calcined ACH-Nontronite had BET surface area of 310 m /g and contained 31.9% FegOj. All powder diffraction measurements were obtained with a Siemens D-500 diffractometer at a scan of r/min using monochromatic Cu-Ka radiation. 

The catalytic and structural properties of two chromia-pillared montmorillonites were compared in an effort to establish structure-reactivity relationships in these materials. The basal spacings of pillared products, prepared by reaction of Na+-montmorillonite with base-... 

Pillaring solutions. Conventional Al203-pillared montmorillonite and interstratified illite/montmorillonites were prepared using an aluminum chlorohydrate (ACH) solution having an Al-concentration of 0.25 M and an OH/Al-ratio of 2.5, prepared by dilution of a commercial ACH-solution (Locron L, Hoechst). The solution was aged for 20 hr. after dilution, prior to use for preparation of pillared products. 

Preparation of pillared products. The conventional pillared montmorillonite and the pillared interstratified I/M were prepared by addition of a volume of the ACH-solution calculated to give an Al/clay ratio of 5 mmoles per g to a dispersion (1 g/1) of the clay. 

Silicon oxide / Aluminum oxide pillared smectites. Si02/Al203-pillared smectites were prepared using two different methods (6). The surface areas of the pillared products decreased with increasing Si/Al-ratio in the pillaring solution while the basal spacings were essentially independent of this ratio. 

It can be considered that these pillared products will be intercalated by accompanying with proton to produce a solid acid catalyst, because they exhibited acidity as shown in Table 1. To examine the acidic property of the catalysts dehydrations of methanol and 1-butanol were attempted by a flow reactor. The dehydration products of methanol were dimethyl ether and water, and those of 1-butanol were 1-, cis-2-, and trans-2-butenes and water. At relatively low temperature (250°C to 300°C) in hydration of 1-butanol a... 

The calcined pillared product exhibits XRD characteristics similar to the swollen material with the peaks somewhat broadened and slightly shifted due to c-parameter contraction by a few A units. 

NOa" precursor (cIqqi = 8.9 A) and the 12, 40 pillared product (doQi = 14.5 A) exhibited IQW patterns with at least six orders of 001 harmonics. The basal spacing for the pillared product was indicative of a gallery height of 9.8 A, in accord with the expected size of the Keggin ion. Both pillared derivatives exhibited Langmuir - type N2 adsorption isotherms indicative of microporous structures. 

The intercalation of imogolite monolayers in smectite cogently demonstrates the concept of forming regular, supergallery pillared products by direct intercalation on metal oxide sol particles of regular size and shape. 

A reference sample was prepared by not adding boron acid into gel, and the pillared product was designated as A1-PSBCS(0). 

Alumina-pillared synthetic boron-containing s qx)nite was prepared for the first time. The introduction of boron into the S2qx)nite layers markedly enhanced both cumene dealkylation activity and benzene selectivity of its pillared product The pillared product of synthetic boron-containing saponite was pillared clay rather than delaminated clay. 

This study describes two methods to prepare well-ordered adipate-pillared hydrotalcite-like LDHs. One is the ion-exchange method, the other is the coprecipitation method. The former has not been reported before. As to the latter, products with diffuse or amorphous X-ray patterns were previously observed (Drezdzon 1988 Reichle 1985). These organic-pillared LDHs served as precursors and were ion-exchanged with tetraborate ions. The resultant pillared hydrotalcite-like LDHs had fairly good crystallinity. This is ascribed to tetraborate anions being stable under mildly basic conditions. The variables in preparation conditions which might influence the pillared products were examined. The catalytic activity of the pillared material in 2-butanol decomposition reaction was also discussed. 

These layered phosphates do not swell in water. Therefore, the layers were first spread apart by intercalation of butylamine. In this condition the AI13 species was exchanged for the alkylammonium ion to form pillared products [19]. Table 12-1 gives a summary of some of the results obtained with zirconium phosphate. It is observed that the surface areas of the aluminum... 

N03] precursor and (B) the [Zn2Al(OH)g][H2Wj204012/5 pillared product formed by ion exchange. 

---