ment was conducted using HC1O$_{4 }$ as an acid in methanol solvent under the same conditions as Example 1 except for atmosphere. The amount ofHClO$_{4 }$ was f=l .25. The products were identified and the amounts of residual carbonate ions were measured by FTIR, and the amounts of residual carbon› ate ions in both products were 3% or lower. 

[0240] Then, using NH$_{4}$Cl as ammonium salt, experiment was conducted in methanol under the same conditions as Example 9 except for atmosphere. The amount ofNH$_{4}$Cl was f=3. The amount ofresidual carbonate ions in the product was 20%. 

[0241] In addition, using dimethylamine hydrochloride as amine acid salt, experiment was conducted in ethanol under the same conditions as Example 10 except for atmosphere. The amount of dimethylamine hydrochloride was f=3. The amount of residual carbonate ions in the product was 10%. 

[0242] The results described above indicate that when acids were used, no effect of the atmosphere was observed whether nitrogen gas flow or air flow adopted; however, when amine acid salt were used, the atmosphere was found to have effect, and the amount of residual carbonate ions was larger for the reaction performed in air flow. 

## Ammonium Acetate-Methanol, Ethanol System 

[0243] Experiment was conducted regarding a case where x- was CH$_{3}$Coo- (acetate ion). The obtained LDH is easily anion-exchangeable acetate ion-type LDH.As an acidic com› pound, ammonium acetate (CH$_{3}$COONH$_{4}$ ) was used. Ammonium acetate is represented as CH$_{3}$COOH.NH$_{3 }$ in NRR’R".HX because R=R’=R"=H and X=CH$_{3}$COO. The amount of ammonium acetate is represented as f=[H+]/ (2x[CO$_{3 }$$^{2}$-])=[CH$_{3}$COONH$_{4}$ ]/(2x[CO$_{3 }$ 2 -]). 

[0244] Reaction was performed in methanol containing ammonium acetate (CH$_{3}$COONH$_{4}$ ). 100 mg (0.331 mmol) of CO$_{3 }$$^{2}$-MgAl-LDH3 was poured in a three-neck flask, to which 40 mL of methanol was added and dispersed ultrasoni› cally to prepare suspended liquid. While this suspended liq› uid was being agitated with a magnetic stirrer, a solution prepared by dissolving ammonium acetate off=S (Cica spe› cial grade) (204.2 mg; 2.65 mmol) in 10 mL of methanol was added to the liquid under nitrogen gas flow (0.5 Umin.) Reaction was performed at room temperatures (20 to 25° C.) for 2 hours by agitating the co/-MgAl-LDH3 suspended liquid under nitrogen gas flow using a magnetic stirrer. A large amount of CO$_{2 }$due to decarbonation was found in outlet nitrogen gas. By filtration and drying performed under the same conditions as Example 1, white powder was obtained. 

[0245] FTIR confirmed generation of acetate ion-type LDH, and no residual carbonate ions were found. 

[0246] Experiments were conducted under conditions other than f=S described above, namely under f=4, 6, and 10 conditions. When f=4 and 6, slight amount of residual car› bonate ions was found. When f= 10, FTIR did not confirm the existence of residual carbonate ions. 

[0247] When f=S and 10, the yield was quantitative, and even when the amount 10 times that of the original was used, no weight loss due to dissolution was found. 

[0248] For comparison, experiment was conducted using sodium acetate, which has no ability to release protons, under the same conditions. Sodium acetate of the amount equivalent to f=[CH$_{3}$COONa ]/(2x[Co/-])=8, namely 217 .3 mg, was used. To CO$_{3 }$$^{2}$-MgAl-LDH3 suspended liquid, methanol 

## Example 14 

solution of f=S sodium acetate was added while the liquid was being agitated in nitrogen gas flow using a magnetic stirrer, and reaction was performed at room temperatures (20 to 25° C.) for 2 hours. No CO$_{2 }$was found in outlet nitrogen gas. By filtration and drying conducted under the same conditions as Experiment 1, white powder was obtained. 

[0249] Although FTIR confirmed inclusion of acetate ions of several %, the profile was basically that of carbonate ion› type LDH. 

[0250] From the above, it is apparent that not all acetate salts can be used but that efficient reactions are ensured only when ammonium salt, namely an acidic compound, is used. 

## Synthesis of Acetate Ion-Type LDH Using Acetic Acid 

[0251] Using acetic acid (X=CH$_{3}$COO in CH$_{3}$COOH. HX) as an acidic compound, acetate ion-type LDH was syn› thesized by decarbonation under the same conditions as Example 14. Reaction was performed for 1 to 2 hours at room temperatures (20 to 25° C.) using acetic acid of the amounts f=[CH$_{3}$COOH]/(2x[CO$_{3 }$$^{2}$-])=2 and 3. In both cases (f=2 and 3), FTIR confirmed the generation of acetate ion-type LDH, and no residual carbonate ions were found. Even when etha› nol was used instead of methanol ( experiment was conducted under f=3 condition), acetate ion-type LDH was generated and no residual carbonate ions were found. 

## Ammonium Acetate-Methanol, Ethanol System; Heating 

[0252] Using ammonium acetate of the amount equivalent to f= 1, reaction was performed in nitrogen gas flow at 45° C. for 2 hours. Experiment was conducted using methanol as a solvent and 100 mg of CO$_{3 }$$^{2}$-MgAl-LDH3 under the same conditions as Example 14. Filtration and drying were con› ducted under the same conditions as Example 1, and white powder was obtained. 

[0253] FTIR confirmed the generation of acetate ion-type LDH, and no residual carbonate ions were found. When etha› nol was used as a solvent, acetate ion-type LDH was gener› ated at 45° C. when the amount of ammonium acetate was f=l, but existence of residual carbonate ions by approxi› mately 5% was found. When the amount of ammonium acetate was increased to f=3, acetate ion-type LDH without residual carbonate ions was synthesized by the reaction caused at 40° C. for 2 hours. 

## Acetic Acid-Methanol, Ethanol System; Heating 

[0254] Using methanol as a solvent and acetic acid of the amount equivalent to f= 1, reaction was performed in nitrogen gas flow at 45° C. for 2 hours. Filtration and drying were conducted under the same conditions as Example 1, and white powder was obtained. FTIR confirmed the generation of acetate ion-type LDH, and no residual carbonate ions were found. Similarly, when ethanol was used as a solvent, acetate ion-type LDH was generated at 45° C. 

## Example 15 

## Example 16 

## Example 17 

