Chemical Reactivity of Formaldehyde in a FeAlPO₄ Sieve

Formaldehyde gas loaded into a framework Fe aluminophosphate sieve (FeAlPO 4 -5) at 250 K was found to react with adsorbed H 2 O, CH 3 OH, H 2 O 2, or lattice OH groups to yield the corresponding addition products, namely, CH 2 (OH) 2, CH 3 OCH 2 OH, HO 2 CH 2 OH, or POCH 2 OH, respectively. Reactions were monitored in situ by static FT-IR spectroscopy, and assignments are based on experiments with CD 2 O and CD 3 OD. Most efficient was the reaction with H 2 O 2, as indicated by the fact that HO 2 CH 2 OH was formed at the exclusion of CH 2 (OH) 2 and POCH 2 OH when adsorbing formaldehyde onto a sieve loaded with H 2 O 2 and H 2 O. Methoxymethanol, methanediol, and POCH 2 OH were stable at 250 K but dissociated above 0 °C under release of formaldehyde. Hydromethyl hydroperoxide disproportionates to formic acid and water. Under 355 nm irradiation in a FeAlPO 4 sieve, HO 2 CH 2 OH was found to undergo efficient photofragmentation.