The disposal of manganese slag and chromium electroplating wastewater is a difficult problem worldwide. These wastes contain various transition metals, such as Mn, Cr, Fe, Ni and Cu. Thus, these wastes are also potential resources. In this work, a novel catalyst for selective catalytic reduction of nitric oxide was synthesized with the synergetic utilization of manganese slag and chromium wastewater for the first time. The catalyst was feathered by a multi-metal containing amorphous and crystal MnCr oxides. As a result, the manganese slag after ammonia activation increased the removal of nitric oxide from 25 to 61% at a temperature as low as 150 °C. The nitric oxide removal further increased to 97% after chromium wastewater precipitation. The enhanced efficiency lasted for more than 900 min. The results of X-ray diffraction, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy revealed that chromium wastewater increased the amount of amorphous Mn⁴⁺, which coupled to Cr³⁺. Moreover, the Ni, Fe and Cu in Mn slag and Cr wastewater were incorporated into the coupling, further enhancing the amount of acid sites and low-temperature activity. This catalyst was even more active than a reagent-synthesized MnCr catalyst. Therefore, the present research developed a new strategy to recycle transition metal-containing wastes and to synthesize catalysts for sustainable development.

锰渣和铬电镀废水的处理是世界范围内的难题。这些废物包含各种过渡金属，例如Mn，Cr，Fe，Ni和Cu。因此，这些废物也是潜在的资源。在这项工作中，首次利用锰渣和铬废水的协同利用，合成了一种选择性催化还原一氧化氮的新型催化剂。催化剂由含有非晶态和结晶态MnCr氧化物的多金属制成。结果，氨活化后的锰渣在低至150℃的温度下将一氧化二氮的去除率从25％提高到61％。铬废水沉淀后，一氧化氮的去除率进一步提高到97％。效率提高持续了900多分钟。X射线衍射的结果⁴⁺，其与Cr ³⁺耦合。此外，锰渣和铬废水中的镍，铁和铜也被引入到耦合中，进一步增加了酸位的数量和低温活性。该催化剂比试剂合成的MnCr催化剂更具活性。因此，本研究开发了一种新的策略，以回收含过渡金属的废物并合成催化剂以实现可持续发展。