Synthesis, Characterization and Catalytic Performance of Ceria-Supported Cobalt Catalyst for Methane Dry Reforming to Syngas

Abstract

In this study the synthesis, characterization and catalytic performance of CeO 2 (Ceria) supported Co catalyst was investigated. First, the ceria was synthesized by direct thermal decomposition of Ce(NO 3 ) 3 .6H 2 O and subsequently impregnated with 20 wt.% Co using aqueous solution of Co(NO 3 ) 2 .6H 2 O as a precursor. The synthesized catalyst was characterized using TGA, N 2 -adsorption-desorption, X-ray Diffractometry (XRD), Field Emission Scanning Electron Microscope (FESEM-EDX), and Fourier Transformation Infrared (FTIR). The catalytic property of the ceria-supported cobalt catalyst was tested in methane dry reforming using a stainless steel fixed bed reactor. The dry reforming reaction was performed at the temperature range of 923-1023 K under a controlled atmospheric pressure and constant gas hourly space velocity (GHSV) of 30000 h -1 . The effects of reactant (CH 4 and CO 2 ) feed ratio was investigated on reactants conversion, product yields, and selectivity. The ceria-supported cobalt catalyst recorded highest catalytic activity at a CH 4 : CO 2 ratio of 0.9 and temperature of 1023 K. The highest values of 79.5% and 87.6% were recorded for the CH 4 and CO 2 conversions respectively. Furthermore, highest yields of 41.98% and 39.76%, as well as selectivity of 19.56% and 20.72%, were obtained for H 2 and CO respectively. Syngas ratio of 0.90 was obtained from the dry reforming of methane, making it suitable as feedstock for Fischer-Tropsch synthesis (FTS). Keywords: ceria, cobalt, Fischer-Trosch synthesis, methane dry reforming, syngas AbstrakDalam kajian ini, sintesis, pencirian berserta prestasi tindakbalas pemangkin Co/CeO 2 telah dijalankan. Terdahulu, ceria disintesis daripada penguraian terma secara langsung ke atas Ce(NO 3 ) 3 .6H 2 O, diikuti oleh formulasi dengan 20% logam Co menggunakan larutan akueus Co(NO 3 ) 2 .6H 2 O sebagai pelopor. Mangkin yang diperolehi dicirikan dengan menggunakan kaedah TGA, N 2 -penjerapan penyaherapan, pembelauan sinar X (XRD), Mikroskop Pengimbas Elektron Pancaran Medan -Sinar-X Serakan Tenagan (FESEM-EDX) dan Inframerah Tranformasi Fourier (FTIR). Prestasi pemangkin Co/CeO 2 telah diuji untuk tindakbalas penghasilan metana kontang di dalam reaktor keluli tahan karat. Tindakbalas kimia tersebut telah dijalankan pada suhu berjulat daripada 923-1023 K, tekanan 1 atm serta GHSV bersamaan 30000 h -1 . Kesan nisbah reaktan (CH 4 and CO 2 ) terhadap penukaran reaktan serta hasil dan pemilihan produk telah disiasat. Mangkin Co/CeO 2 mencatatkan aktiviti pemangkin paling tinggi pada nisbah CH 4 /CO 2 bersamaan 0.9 dan suhu 1023 K. Penukaran CH 4 and CO 2 mencatatkan nilai tertinggi bersamaan 79.5% dan 87.6%. Tambahan pula, hasil tertinggi bersamaan 37.6% dan 40% berserta sifat pemilihan bersamaan 19.56% dan 20.72% untuk H 2 dan CO telah direkodkan. Nisbah gas sintesis bersamaan 0.9 telah diperolehi daripada penghasilan semula metana kontang bersesuaian untuk tindakbalas sintesis Fischer-Trosch.