02499nas a2200265   4500008004100000022001400041245014800055210006900203260000800272300001100280490000800291520156300299653001901862653001801881653002401899653001301923653002601936653002701962100002201989700001802011700002302029700002302052700002702075856013102102       2020                        eng d  a0045-653500aScreening of zero valent mono/bimetallic catalysts and recommendation of Raney Ni (without reducing agent) for dechlorination of 4-chlorophenol0 aScreening of zero valent monobimetallic catalysts and recommenda  cJUL  a1262980 v2503 a<p>Chlorophenol (CP) is considered as environmentally hazardous material due to its acute toxicity, persistent nature and strong bioaccumulation. The dechlorination of 4-CP was investigated by using various catalysts such as bimetallic (Fe-0/Cu-0, Al-0/Fe-0), Pd/C, Raney Ni and Fe-0 at room temperature. Among the catalysts studied, Raney Ni proved to be very economical and efficient catalyst that worked without the use of an external reducing agent. The dechlorination of 4-CP by Raney Ni was therefore further explored. Complete dechlorination of 4-CP (30 mg L-1) was achieved in 6 hat an optimum Raney Ni catalyst loading of 3 g L-1. The effect of triethylamine (TEA) and tripropylamine (TPA) was also investigated and it was observed that 100% dechlorination is possible in presence of 45 mg L-1 of TEA. The kinetics of dechlorination of 4-CP was investigated and found to be first order with a rate constant of 0.017 min(-1) at 50 degrees C, and it enhances to 0.109 min(-1) with addition of TEA. In the absence of a reducing agent, acidic to neutral pH favors dechlorination of 4-CP. The final product of dechlorination was estimated to be phenol by performing HPLC, LCMS and NMR analysis. Based on the results, a probable dechlorination mechanism of 4-CP is also proposed. It can be concluded that the catalytic hydrodechlorination is an effective and economical technique for dechlorination of 4-CP and it has a potential for the dechlorination of other toxic derivatives of chlorinated aromatics. (C) 2020 Elsevier Ltd. All rights reserved.</p>
10a4-Chlorophenol10aCl- scavenger10aHydrodechlorination10aRaney Ni10aRecycling of catalyst10aWithout reducing agent1 aRaut, Sandesh, S.1 aShetty, Rohit1 aRaju, Nikhi, Maria1 aKamble, Sanjay, P.1 aKulkarni, Prashant, S.  uhttps://library.ncl.res.in/content/screening-zero-valent-monobimetallic-catalysts-and-recommendation-raney-ni-without-reducing