Benzoic acid as a selector–modulator in the synthesis of MIL-88B(Cr) and nano-MIL-101(Cr). Issue 3 (21st December 2018)

• Record Type: Journal Article
• Authors: Yang, Ling; Zhao, Tian; Boldog, Ishtvan; Janiak, Christoph; Yang, Xiao-Yu; Li, Qiang; Zhou, Yan-Jia; Xia, Yong; Lai, Deng-Wang; Liu, Yue-Jun
• Is Part Of: Dalton transactions. Volume 48:Issue 3(2018)
• Page Start: 989
• Page End: 996
• Publication Date: 2018-12-21
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c8dt04186e
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The concentration of benzoic acid was found to exercise efficient control over the formation of either MIL-101(Cr) or MIL-88B(Cr) under otherwise similar hydrothermal synthetic conditions. Abstract : The concentration of benzoic acid was found to exercise efficient control over the formation of either MIL-101(Cr) or MIL-88B(Cr) under otherwise similar hydrothermal synthetic conditions. Nanocrystals of MIL-101(Cr) with ∼100 nm average size and excellent S BET = 3467 m 2 g −1 are obtained at lower concentrations of benzoic acid, while at higher concentrations the microparticulated MIL-88B(Cr) product is formed. Hereby a new efficient synthetic method towards the elusive MIL-88B(Cr), yet reported only once without synthetic details, is proposed. The obtained MIL-88B(Cr) has an interesting and potentially valuable property of retaining its high-volume form ( V cell ∼ 2000 Å 3 ) after thermal activation. The degassing of MIL-88B(Cr) in a vacuum at 250 °C yields a porous material with a S BET area of 1136 m 2 g −1, which is around the theoretical maximum. The transition to the denser 'closed' form ( V cell ∼ 1500 Å 3 ) occurs only at 350 °C, when all of the benzoate/benzoic acid, hindering the process, is removed.