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Iron doped aluminophosphate molecular sieve with improved adsorption capacity for water vapor

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Yanshu Luo
Yanshu Luo
Yanshu Luo
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Xianghui Liang
Xianghui Liang
Xianghui Liang
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Xueqing Li
Xueqing Li
Xueqing Li
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Shuangfeng Wang
Shuangfeng Wang
Shuangfeng Wang
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Abstract and Figures

With a characteristic of S-shape isotherms for water vapor adsorption, aluminophosphate molecular sieve with AFI type (AlPO-5) has been considered as an up-and-coming adsorbent for the utilization in the adsorption cooling and heating (ACH) system. In order to improve its adsorption performance, iron doped AlPO-5 (FeAPO-5) with variable Fe loading was synthesized by microwave hydrothermal method. The effects of the iron doping content on the structure and adsorption performance were systematically investigated. The analysis results of X-ray diffraction (XRD), UV–visible spectroscopy (UV–Vis-DR) and scanning electron microscopy (SEM) showed that the iron ion was incorporated into aluminophosphate molecular sieves with a typical AFI structure as that of AlPO-5 through the isomorphous substitution. As the iron content of FeAlPO-5s increased, the isolated FeIII decreased, while oligonuclear FeIII and nanosized FeIII increased, besides, the static adsorption curves showed that the adsorption capacity of FeAlPO-5 increased first and then decrease. After iron modifying, the crystallinity and morphology of crystals was improved, and the adsorption performance increased from 0.185 g/g (AlPO-5A) to 0.235 g/g (FeAlPO-5), while the desorption performance of FeAlPO-5 (95.69 kJ/mol) was close to that of AlPO-5A (81.59 kJ/mol).
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Adsorption (2018) 24:551–561
https://doi.org/10.1007/s10450-018-9966-x
Iron doped aluminophosphate molecular sieve withimproved
adsorption capacity forwater vapor
YanshuLuo1· XianghuiLiang1· XueqingLi1· ShuangfengWang1· XuenongGao1· ZhengguoZhang1·
YutangFang1
Received: 3 February 2018 / Revised: 10 May 2018 / Accepted: 30 July 2018 / Published online: 1 August 2018
© Springer Science+Business Media, LLC, part of Springer Nature 2018
Abstract
With a characteristic of S-shape isotherms for water vapor adsorption, aluminophosphate molecular sieve with AFI type
(AlPO-5) has been considered as an up-and-coming adsorbent for the utilization in the adsorption cooling and heating
(ACH) system. In order to improve its adsorption performance, iron doped AlPO-5 (FeAPO-5) with variable Fe loading
was synthesized by microwave hydrothermal method. The effects of the iron doping content on the structure and adsorption
performance were systematically investigated. The analysis results of X-ray diffraction (XRD), UV–visible spectroscopy
(UV–Vis-DR) and scanning electron microscopy (SEM) showed that the iron ion was incorporated into aluminophosphate
molecular sieves with a typical AFI structure as that of AlPO-5 through the isomorphous substitution. As the iron content of
FeAlPO-5s increased, the isolated FeIII decreased, while oligonuclear FeIII and nanosized FeIII increased, besides, the static
adsorption curves showed that the adsorption capacity of FeAlPO-5 increased first and then decrease. After iron modify-
ing, the crystallinity and morphology of crystals was improved, and the adsorption performance increased from 0.185g/g
(AlPO-5A) to 0.235g/g (FeAlPO-5), while the desorption performance of FeAlPO-5 (95.69kJ/mol) was close to that of
AlPO-5A (81.59kJ/mol).
Keywords Iron containing AlPO4-5· Microwave irradiation· Iron species· Adsorption and desorption performance·
Desorption activated energy· ACH system
Abbreviations
ACH Adsorption cooling and heating
SEM Scanning electron microscopy
UV–Vis-DR UV–visible spectroscopy
XRD X-ray diffractometer
* Yutang Fang
ppytfang@scut.edu.cn
Extended author information available on the last page of the article
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Several heterogeneous catalysts have been reported to be active in vapor-phase Omethylation of catechol and methanol, including pure and doped metal oxides [6][7][8], supported tungsten compound [9] and metal phosphates [10][11][12][13][14][15][16], etc. Amorphous aluminophosphates, which possess both acid and base sites, are considered effective catalysts for vapor-phase O-methylation of catechol with methanol [12][13][14][15][16]. The physicochemical properties of aluminophosphate have been reported to depend on modifying catalyst with various metals, optimizing catalyst compositions, and improving catalyst preparation routes [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Generally, aluminophosphates with specific structure are usually synthesized with various surfactant templates. ...
... Hence, it is still important to develop a simple approach to fabricate aluminophosphates with high activity and selectivity for vaporphase O-methylation of catechol with methanol. It is commonly acknowledged that various metals, especially transition metal, introduced to aluminophosphates could alter the acid-base property of aluminophosphates [17][18][19][20][21][22][23][24][25][26]. ...
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