Utilization Of Spent Catalyst Ni/γ-Al2O3 In Nickel Oxalate Synthesis: Effect Of pH

Nickel-based compounds play an essential role as one of the materials for manufacturing rechargeable battery electrodes. One compound that has the potential to be used is nickel oxalate. This study investigates using the spent catalyst Ni/γ − Al2O3 as a raw material to produce nickel oxalate. The spent catalyst acts as a nickel source in the precursor solution. The spent catalyst was leached first, and then a two-step precipitation process was conducted to synthesize nickel oxalate. The first precipitation process took place at pH 6 using a sodium hydroxide (NaOH) solution to remove all aluminum (Al) contaminants. Meanwhile, the remaining precursor solution was dripped with an oxalic acid solution to produce nickel oxalate. For the second precipitation, this study varied the pH of the solution between 1-5. The experimental results proved that almost all Ni (II) ions were successfully precipitated. Optimum operating conditions were reached when the pH of the solution was 1 and the precipitation process lasted for 24 hours. The precipitate formed was then analyzed to determine the characteristic of the precipitate. The characterization results showed that the precipitate had a purity of 96.06Ni. Overall, the precipitate was still experiencing an agglomeration phenomenon. In the future, this phenomenon needs to be prevented using surfactants or sonicators. However, this study proves that the spent catalyst has extraordinary potency to be utilized as a raw material to manufacture nickel-based compounds. © 2024 Tamkang University. All rights reserved.