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Summary Catalytic stability with time‐on‐stream is an important aspect in ethanol dry reforming (EDR) since catalysts could encounter undesirable deterioration arising from deposited carbon. This work examined the promotional effect of La on 10%Co/Al2O3 in terms of activity, stability, and characteristics. Catalysts were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman, and X‐ray photoelectron spectroscopy (XPS) measurements whilst catalytic EDR performance of La‐promoted and unpromoted 10%Co/Al2O3 prepared via wet impregnation technique was investigated at 973 K for 72 h using a stoichiometric feed ratio (C2H5OH/CO2 = 1/1). La promoter substantially enhanced both metal dispersion and metal surface area from 0.11% to 0.64% and 0.08 to 0.43 m2 g−1, respectively. Ethanol and CO2 conversions appeared to be stable within 50 to 72 h after experiencing an initial activity drop. The conversion of C2H5OH and CO2 for La‐promoted catalyst was about 1.65 and 1.34 times greater than unpromoted counterpart in this order. The carbonaceous deposition was considerably decreased from 55.6% to 36.8% with La promotion due to La2O2CO3 intermediate formation. Additionally, 3%La‐10%Co/Al2O3 possessed greater oxygen vacancies acting as active sites for CO2 adsorption and hence increasing carbon gasification. Even though graphitic and filamentous carbons were formed on used catalyst surface, La‐addition diminished graphite formation and increased the reactiveness of amorphous carbon.

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La-promoted and unpromoted 10%Co/Al2O3 catalysts were synthesized using wet a impregnation method and evaluated in a quartz fixed-bed reactor at different CO2:C2H5OH ratios of 2.5:1-1:2.5 and a reaction temperature of 973 K under atmospheric pressure. X-ray diffraction measurements detected the presence of Co3O4 and CoAl2O4 phases on the surface of both promoted and unpromoted catalysts. BET surface area of promoted and unpromoted 10%Co/Al2O3 catalysts was about 143.09 and 136.04 m2.g-1, respectively. The La promoter facilitated Co3O4 reduction, improved the degree of reduction from 86 to 98% and increased metal dispersion from 9.11% to 16.64%. The La-promoted catalyst appeared to be a better catalyst in terms of catalytic activity and product yield regardless of reactant partial pressure. Both C2H5OH and CO2 conversions improved significantly with an increase in CO2 partial pressure from 20 to 50 kPa for both catalysts whilst a decline in catalytic performance was observed with rising C2H5OH partial pressure. La addition improved C2H5OH and CO2 conversions up to about 74.22% and 33.80%, respectively. ABSTRAK: Penggalak-La dan bukan penggalak-La mangkin 10%Co/Al2O3 dihasilkan menggunakan kaedah impregnasi basah dan dinilai dalam reaktor alas-tetap quarza pada pelbagai nisbah CO2:C2H5OH sebanyak 2.5:1-1:2.5 dan suhu tindak balas sebanyak 973 K di bawah tekanan atmosfera. Hasil daripada ukuran pembelauan X-ray, didapati terdapat kehadiran fasa Co3O4 dan CoAl2O4 pada permukaan kedua-dua mangkin penggalak dan bukan penggalak. Permukaan kawasan BET pada penggalak dan bukan penggalak mangkin 10%Co/Al2O3 adalah masing-masing sebanyak 143.09 dan 136.04 m2.g-1. Penggalak-La membantu dalam pengurangan Co3O4,membaiki peratus penurunan daripada 86 kepada 98% dan menambah penyebaran logam daripada 9.11% kepada 16.64%. Mangkin penggalak-La dilihat sebagai mangkin terbaik dari segi aktiviti pemangkinan dan hasil pengeluaran, biarpun pada tekanan separa reaktan. Kedua-dua penukaran C2H5OH dan CO2 meningkat dengan ketara dengan kenaikan separa tekanan CO2 daripada 20 kepada 50 kPa bagi kedua-dua pemangkin, sementara penurunan dalam aktiviti pemangkinan dilihat dengan kenaikan tekanan separa C2H5OH. Penambahan La meningkatkan penukaran C2H5OH dan CO2, masing-masing sebanyak 74.22% dan 33.80%.

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