Silver nanoparticles (AgNPs) are increasingly drawing a great deal of attention because of their exclusive properties and a huge variety of applications. In recent years, using AgNPs supported on various carriers as heterogeneous catalysts has become promising for treating some toxic gases in the environment, such as HCHO. This study has successfully synthesized AgNPs onto ZSM-5 microporous zeolite and ZSM-5 mesopore-modified zeolite (Meso-ZSM-5) by ion-exchange method using sodium borohydride as a reducing agent. The resulting catalysts were then characterized by N2 adsorption-desorption method. In order to evaluate HCHO adsorption, desorption, and the surface reaction of these catalysts, temperature-programmed desorption (TPD) and temperature-programmed surface reaction (TPSR) were employed. The TPD and TPSR experiments were conducted with different relative humidity. The results showed that Ag/Meso-ZSM-5 exhibited higher catalyst activity in HCHO complete oxidation than Ag/ZSM-5 at high temperatures because of a new larger pore system within the zeolite. Furthermore, TPD and TPSR experiments provided an explanation for the poor performance of the catalysts at low temperatures, which was associated with the high adsorption capacity of the zeolite.

Cellulose aerogels are a potential candidate for heat insulation, but one of their drawbacks is high flammability hindering their applications in practice. This study synthesized cellulose aerogels from microfibrillated cellulose fibers (MFC) extracted from discarded pineapple leaves. The procedure started with simply mixing the extracted fibers with polyamide amine-epichlorohydrin (PAE) as a chemical crosslinker and ammonium polyphosphate (APP) (10-20%) as a green and effectively flame-resistant additive, followed by freeze-drying. The produced aerogels are characterized in terms of their morphology, thermal stability and conductivity, and flame resistance via advanced and standardized methodologies including Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), thermal conductivity measurement by a heat flow meter, and UL94 horizontal burning test. The flame-resistant cellulose aerogels exhibit ultra-low density (25.5-26.8 mg/cm3), high porosity (98.0-98.2%), excellent heat insulation (35.9-36.7 mW/m۰K), and are completely flame-resistant. In addition, the varied APP content (10-20%) shows little effect on the density, heat conductivity, and thermal stability of the flame-resistant cellulose aerogels in comparison with that of the neat cellulose aerogel. Based on the findings, the synthesized flame-resistant cellulose aerogels are considered a promising bio-based heat insulation material.