Dehydration of lactic acid to acrylic acid over lanthanum phosphate catalysts: the role of Lewis acid sites

Abstract

Lanthanum phosphate (LaP) nano-rods were synthesized using n-butylamine as a shape-directing agent (SDA). The resulting catalysts were applied in the dehydration of lactic acid to acrylic acid. Aiming to understand the nature of the active sites, the chemical and physical properties of LaP materials were studied using a variety of characterization techniques. This study showed that the SDA not only affected the porosity of the LaP materials but also modified the acid-base properties. Clearly, the modification of the acid-base properties played a more critical role in determining the catalytic performance than porosity. An optimized catalytic performance was obtained on the LaP catalyst with a higher concentration of Lewis acid sites. Basic sites showed negative effects on the stability of the catalysts. Good stability was achieved when the catalyst was prepared using the appropriate SDA/La ratio.

Bio‐Acrylates Production: Recent Catalytic Advances and Perspectives of the Use of Lactic Acid and Their Derivates

“…In addition to the previously mentioned alkaline‐earth phosphate materials, lanthanum and cerium phosphates have also been reported as catalysts yielding AA with 52 and 64 % of selectivity, respectively.…”

Products of sugar beet processing as raw materials for chemicals and biodegradable polymers

“…52 This chemical is also of interest as a chemical platform, and can be subject to multiple transformations. Both small compounds, such as propylene glycol 22,53,54 or acrylic acid, 55,56 and high molecular weight polymers, such as biodegradable poly(lactic acid) polymers can be produced from LA (Fig. 3).…”

In Situ-Generated Supported Potassium Lactate: Stable Catalysis for Vapor-Phase Dehydration of Lactic Acid to Acrylic Acid

“…1,2,7,12−17 Likely, the catalytic performance for the vapor-phase LA conversion promoted investigators to shed light on the LA reaction mechanism and catalytic active species on various catalyst systems. 12,16,18−25 Miller and co-workers earlier studied the vapor-phase LA conversion mechanism on catalyst surfaces by means of IR, NMR, and GC/MS analyses of surface species apart from catalytic testing and kinetics. 18−22,26 They discovered that low temperatures (<320 °C) and elevated pressures favor 2,3-pentanedione (2,3-PD) formation, whereas high temperatures and low pressures benefit AA and CH 3 CHO production.…”