Carbon Aerogel-Supported Nickel and Iron for Gasification Gas Cleaning. Part I: Ammonia Adsorption

Abstract

Biomass gasification is a promising way to obtain “green energy”, but the gas composition makes it unsuitable for use in traditional technologies (i.e., IC engine). Gas purification over nickel and/or iron catalysts is an attractive alternative. Cellulose-based carbon aerogels (CAGs) have shown suitable physical chemical properties for use as catalyst supports. In this work, nickel and iron catalysts are supported on CAG made from cellulose microfibers. Microfibers were impregnated with (NH4)2SO4 to increase the mass yield. Carbonization was evaluated at different heating rates, maximum temperatures, and dwell times to generate CAGs. Resulting chars were characterized by N2 adsorption, X-ray diffraction (XRD), and Raman spectroscopy. The CAG with better properties (specific surface, pore size, thermal resistance) was impregnated with the metal precursor salt via incipient wetness and treated with H2. Catalysts were characterized by transmission electron microscopy (TEM), XRD, N2 adsorption, and inductively coupled plasma optical emission spectrometry (ICP-OES). Ammonia adsorption was studied over CAG and catalysts to estimate the thermodynamic parameters. The impregnation with ((NH4)2SO4 improves thermal resistance of the char obtained from carbonization. The catalysts exhibit higher adsorption capacity than CAG (without metal), indicating chemical interaction between ammonia and metals. The metal-ammonia interaction is stronger on Fe than on Ni catalyst, which is consistent with reported theoretical calculations.

Pd‐Doped Cellulose Carbon Aerogels for Energy Storage Applications

“…A third broad reflection can be observed around 15° which has already been identified in carbon aerogels from cellulose and it is related to the precursor. [ 6 ] This band has also been attributed to aliphatic chains bound to the edges of basal planes of the crystal structure. [ 45–47 ] A decrease in the intensity of this band is observed when the Pd content increases, suggesting the influence of the metal on the decomposition of the aliphatic chains.…”

“…These features make them promising materials in emergent fields of applications, such as energy storage, [ 1,2 ] electrocatalysis, [ 3 ] desalination, [ 4 ] bio‐sensing, [ 5 ] and gasification gas cleaning. [ 6 ]…”

Organic aerogel as electro‐catalytic support in low‐temperature fuel cell

“…18 This is the discovery of a special structure constructed from a network of nanosized particles that are interconnected and provide distinct gains for the fabrication of porous materials. 19,20 Interestingly, almost all of the outcomes of research revealed that organic aerogels used as catalyst supports in low-temperature fuel cell applications stabilize nanosized metal particles, resulting in a strong catalytic action. 21 The texture and pore size resulting in the synthesis method plays a significant role in providing robust catalytic support for fuel cell applications.…”

“…Different forms of aerogel structures, such as micropores, mesopores, and macropores, can be produced 18 . This is the discovery of a special structure constructed from a network of nanosized particles that are interconnected and provide distinct gains for the fabrication of porous materials 19,20 …”

A Remarkable Class of Nanocomposites: Aerogel Supported Bimetallic Nanoparticles

“…TiO 2 /CA was investigated as a photoelectrocatalyst for wastewater treatment (Jin et al, 2011). Ni/CA and Fe/CA were used as ammonia adsorption catalysts for gas purification (Gómez-Cápiro et al, 2018). SnO 2 /GA was used as a NO 2 gas sensor (Liu et al, 2014;Li et al, 2015).…”