The production of dimethyl ether (DME) as compared to methanol from synthesis gas allows for increased conversions in a single pass. A challenge in this process is the combination of methanol synthesis and dehydration functionalities in a single catalyst without mutual negative interference of their performances. Here, we studied the use of hydrated niobium pentoxide (Nb₂O₅·nH₂O) and niobium phosphate (NbOPO₄) in combination with a copper-based methanol synthesis catalyst in the direct synthesis of DME, while gamma-alumina (γ-Al₂O₃) was used as a reference material. The three solid acids combined with the copper-based catalyst proved active and selective in the production of DME, however all of them showed some degree of deactivation throughout the reaction. Characterization of the used catalysts pointed out that while the γ-Al₂O₃-based mixture deactivated most likely due to coke deposition on the alumina and structural changes in the methanol synthesis catalysts, the Nb₂O₅·nH₂O and NbOPO₄-based catalysts lost activity probably as a result of copper migration from the methanol synthesis catalyst to the acid component. In view of the high volume-based activity of the Nb-based solid acids it is concluded that these are promising components for the direct catalytic conversion of synthesis gas to DME.

与甲醇相比，由合成气生产二甲醚（DME）可使单程转化率提高。在该方法中的挑战是在单一催化剂中甲醇合成和脱水功能的组合，而不会对其性能造成相互负面影响。在这里，我们研究了水合五氧化_二铌（Nb ₂ O ₅ · n H ₂ O）和磷酸铌（NbOPO ₄）与铜基甲醇合成催化剂的组合在DME直接合成中的应用，而γ-氧化铝（的γ-Al ₂ ö ₃）用作参考材料。三种固体酸与铜基催化剂相结合在二甲醚的生产中证明具有活性和选择性，但是它们在整个反应过程中均表现出一定程度的失活。所使用的催化剂的表征指出的是，虽然在γ-Al ₂ ö ₃系混合物失活最可能是由于在所述的甲醇合成催化剂，氧化铝和结构改变焦炭沉积，使Nb ₂ ø ₅ · Ñ ħ ₂ O和NbOPO ₄基催化剂失去活性可能是由于铜从甲醇合成催化剂向酸组分的迁移所致。考虑到基于Nb的固体酸的高体积活性，可以得出结论，这些是将合成气直接催化转化为DME的有希望的组分。