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Facile Formation of Lactic Acid from a Triose Sugar in Water over Niobium Oxide with a Deformed Orthorhombic Phase
ACS Catalysis ( IF 11.3 ) Pub Date : 2017-12-05 00:00:00 , DOI: 10.1021/acscatal.7b03003 Kiyotaka Nakajima 1, 2 , Jun Hirata 1 , Minjune Kim 1 , Navneet Kumar Gupta 1, 3 , Toru Murayama 4 , Akihiro Yoshida 5 , Norihito Hiyoshi 6 , Atsushi Fukuoka 1 , Wataru Ueda 5
ACS Catalysis ( IF 11.3 ) Pub Date : 2017-12-05 00:00:00 , DOI: 10.1021/acscatal.7b03003 Kiyotaka Nakajima 1, 2 , Jun Hirata 1 , Minjune Kim 1 , Navneet Kumar Gupta 1, 3 , Toru Murayama 4 , Akihiro Yoshida 5 , Norihito Hiyoshi 6 , Atsushi Fukuoka 1 , Wataru Ueda 5
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Hydrothermal treatment of NH4[NbO(C2O4)2(H2O)2]·nH2O in water at 448 K for 3 days produced crystalline Nb2O5 with a deformed orthorhombic structure and a high surface area (208 m2 g–1). Fourier-transform infrared spectroscopy measurements of pyridine adsorption revealed that the Nb2O5 catalyst has both high densities of Brønsted and Lewis acid sites that can work in the presence of water. One feature of the Nb2O5 catalyst is its high density of water-compatible Lewis acid sites (0.21 mmol g–1), which is much larger than that of Nb2O5·nH2O (0.03 mmol g–1). The Nb2O5 catalyst was studied as a solid acid catalyst for the formation of lactic acid from 1,3-dihydroxyacetone and pyruvaldehyde in water at 373 K, and was determined to be a highly active and selective catalyst, compared with typical acid catalysts (H2SO4, Sc(OTf)3, and Nb2O5·nH2O). A high Lewis acid density with moderate acid strength is a crucial factor for the high catalytic performance exhibited for the former reaction. High densities of both Brønsted and Lewis acid sites in the catalyst promote the fast and selective production of lactic acid in the latter reaction. In addition, Such Lewis acidity of the Nb2O5 is also effective over conventional acid catalysts in xylose dehydration to furfural in water, with respect to reaction rate and furfural selectivity. The combination of aqueous-phase dehydration of xylose over the Nb2O5 and the continuous extraction of furfural with an immiscible organic solvent resulted in a high selectivity toward furfural of ∼78.5% with high xylose conversion (97%).
中文翻译：
正交晶相在氧化铌上由三糖在水中容易地形成乳酸
在448 K的水中对NH 4 [NbO（C 2 O 4）2（H 2 O）2 ]· n H 2 O进行水热处理3天，生成的晶体Nb 2 O 5变形为正交晶结构且表面积较大（208 m 2 g –1）。吡啶吸附的傅里叶变换红外光谱测量表明，Nb 2 O 5催化剂具有高密度的布朗斯台德和路易斯酸位，可以在水存在下起作用。Nb 2 O 5的一项功能催化剂具有高密度的水相容性路易斯酸位点（0.21 mmol g –1），远大于Nb 2 O 5 · n H 2 O（0.03 mmol g –1）。研究了Nb 2 O 5催化剂作为固体酸催化剂，用于在373 K下由1,3-二羟基丙酮和丙酮醛在水中形成乳酸，并且与典型的酸催化剂相比，被确定为高活性和选择性的催化剂。 （H 2 SO 4，Sc（OTf）3和Nb 2 O 5 · n H 2O）。具有中等酸强度的高路易斯酸密度是前一反应所显示的高催化性能的关键因素。催化剂中布朗斯台德和路易斯酸位的高密度促进了后者反应中乳酸的快速选择性生产。另外，就反应速率和糠醛选择性而言，Nb 2 O 5的这种路易斯酸度也比常规酸催化剂对木糖在水中脱水成糠醛有效。木糖在Nb 2 O 5上的水相脱水与不混溶的有机溶剂连续萃取糠醛的结合，导致对糠醛的高选择性（约78.5％）和高木糖转化率（97％）。
更新日期：2017-12-05
中文翻译：
正交晶相在氧化铌上由三糖在水中容易地形成乳酸
在448 K的水中对NH 4 [NbO（C 2 O 4）2（H 2 O）2 ]· n H 2 O进行水热处理3天，生成的晶体Nb 2 O 5变形为正交晶结构且表面积较大（208 m 2 g –1）。吡啶吸附的傅里叶变换红外光谱测量表明，Nb 2 O 5催化剂具有高密度的布朗斯台德和路易斯酸位，可以在水存在下起作用。Nb 2 O 5的一项功能催化剂具有高密度的水相容性路易斯酸位点（0.21 mmol g –1），远大于Nb 2 O 5 · n H 2 O（0.03 mmol g –1）。研究了Nb 2 O 5催化剂作为固体酸催化剂，用于在373 K下由1,3-二羟基丙酮和丙酮醛在水中形成乳酸，并且与典型的酸催化剂相比，被确定为高活性和选择性的催化剂。 （H 2 SO 4，Sc（OTf）3和Nb 2 O 5 · n H 2O）。具有中等酸强度的高路易斯酸密度是前一反应所显示的高催化性能的关键因素。催化剂中布朗斯台德和路易斯酸位的高密度促进了后者反应中乳酸的快速选择性生产。另外，就反应速率和糠醛选择性而言，Nb 2 O 5的这种路易斯酸度也比常规酸催化剂对木糖在水中脱水成糠醛有效。木糖在Nb 2 O 5上的水相脱水与不混溶的有机溶剂连续萃取糠醛的结合，导致对糠醛的高选择性（约78.5％）和高木糖转化率（97％）。
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