Nickel doped ZIF-67 catalyst for the catalytic reduction of environmental pollutant, 4-nitrophenol

Background: Bimetallic synthesis is a promising method to improve the properties of zeolitic imidazole frameworks such as ZIF -67 for catalytic applications. The study aimed to synthesize highly efficient and stable catalyst Ni-doped ZIF -67 by bimetallic facile synthesis of ZIF -67 at room conditions and to use for the catalytic reduction reaction of 4-nitrophenol (4-NP), which is a highly toxic component for the environment, in the presence of NaBH 4 as reducing agent. Methods: Different amounts of nickel were added during the synthesis of ZIF -67. The structure of catalysts was elucidated using different characterization methods (SEM, FTIR, TGA, N 2 adsorption, XRD, and XPS). Significant findings: Ni 0.3 @ZIF-67 exhibited the highest reduction efficiency with excellent stability. The obtained results denoted that the catalytic activity was improved by the increasing amount of nickel and the required complete reduction time was determined as 2 min. The obtained rate constants values of reaction are 0.716 min -1 , 1.156 min -1 , and 1.945 min -1 according to the pseudo-first-order mechanism for 30 degrees C, 40 degrees C, and 50 degrees C, respectively. Heterogeneous catalyst formed by doping Ni to ZIF -67 can be a promising way for the reduction of 4-NP to 4-AP.