Pt-MgZnCuAl hydrotalcite-derived catalysts in the reduction of nitrates using continuous and batch reactors

The role of acid–base properties and reconstruction degree of the hydrotalcite-derived materials (MgZnCuAl) in the catalytic hydrogenation of nitrates reaction is studied. In addition, the catalysts have been tested in a batch and continuous reactor to evaluate the influence of the reactor configuration on the catalytic performance. The characterizations of the samples have been performed by XRD, TPR, BET, TEM and MBOH test reaction. A clearly influence of the acid–base properties of the catalysts, modulated by the Zn incorporation, is observed with an increase in the nitrogen selectivity. Besides the common operational parameter differences between work in continuous and discontinuous systems, it shows great differences in the reconstruction degree of the samples. Higher reconstruction leads to higher nitrate reduction and a decrease of nitrite production.

Figure optionsDownload high-quality image (124 K)Download as PowerPoint slideHighlights
► Incorporation of Zn in the hydrotalcite structure decrease the basicity of the sample.
► Increasing the acidity in the catalyst, selectivity toward N2 is increased.
► Batch reactor leads to higher reconstruction degree of LDH phase than in continuous one.
► Higher reconstruction improve the nitrate removal and decrease the presence of intermediate nitrite.