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All Journal Indonesian Journal of Chemistry

Ria Armunanto

Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia

Author-ID : 3960252

Chemical Engineering, Chemistry & Bioengineering Chemistry

Published : 3 Documents Claim Missing Document

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Articles

Hydrocracking of α-Cellulose Using Co, Ni, and Pd Supported on Mordenite Catalysts Wega Trisunaryanti; Triyono Triyono; Ria Armunanto; Lathifah Puji Hastuti; Desinta Dwi Ristiana; Resi Vita Ginting
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

Hydrocracking of α-cellulose has been conducted in a semi-batch reactor at 400, 450, and 500 °C with hydrogen flow (30 mL/min.) for 4 h. Mordenite (MOR) and Co, Ni and Pd metal supported on the MOR were used as solid catalysts. The catalysts were characterized using X-ray Diffractometer (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM) to evaluate the physical-chemical properties. Energy Dispersive X-ray (EDX) and Inductively Coupled Plasma (ICP) were used to analyze the amount of metal impregnated on the catalysts. The liquid product was analyzed using Gas Chromatograph-Mass Spectroscopy (GC-MS). Thermal hydrocracking was also conducted at 450 °C with the amount of liquid product was 37.86 wt.%. The highest liquid conversion obtained by mordenite catalyst was 94.66 wt.% at 450 °C and the highest liquid conversion (98.08 wt.%) was reached by Pd/MOR catalyst at 400 °C.

QMCF-MD Simulation and NBO Analysis of K(I) Ion in Liquid Ammonia Yuniawan Hidayat; Ria Armunanto; Harno Dwi Pranowo
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

Ab initio of Quantum Mechanics Charge Field Molecular Dynamic (QMCF-MD) of K(I) ion in liquid ammonia has been studied. A Hartree-Fock level of theory was coupled with LANL2DZ ECP basis set for K(I) ion and DZP (Dunning) for ammonia. Two regions as first and second solvation shell were observed. In the first solvation shell at distance 3.7 (Å), K(I) ion was coordinated by four to eight ammonia molecules dominated by K(NH3)6+ species. Second shell of solvation was ranging between 3.7 Å to 7.3 Å. Within simulation time of 20 ps, the frequent exchange processes of ligands indicating for a very labile solvation structure. Four mechanism types of ligand exchange between first and second solvation shell were observed. Mean residence time of ligand is less than 2 ps confirming weak in ion-ligand interaction. Evaluation of K(NH3)6+ using natural bond orbital analysis shows that the Wiberg bond Index is less than 0.05 indicating weak electrostatic interaction of K-N.

Investigation of the Structural and Dynamical Properties of Cu+ in Liquid Ammonia: A Quantum Mechanical Charge Field (QMCF) Molecular Dynamics Study Wahyu Dita Saputri; Karna Wijaya; Ria Armunanto
Indonesian Journal of Chemistry Vol 17, No 3 (2017)
Publisher : Universitas Gadjah Mada

A quantum mechanical charge field (QMCF) molecular dynamics (MD) simulation has been carried out to describe the structural and dynamical properties of Cu+ ion in liquid ammonia. The first and second shells were treated by ab initio quantum mechanics at the Hartree−Fock (HF) level with the DZP-Dunning basis set for ammonia and LANL2DZ ECP basis set for Cu. The system was equilibrated for 4 ps, then the trajectory data was collected every fifth step for 20 ps at 235.15 K. The structural analysis showed that in the first solvation shell, Cu+ is solvated by 4 ammonia molecules forming a stable structure of tetrahedral with Cu-N bond length of 2.15 Å, whereas in the second solvation shell there are 29 ammonia molecules that have an average distance of 4.79 Å to Cu+ ion. Mean residence time of 3.06 ps was observed for the ammonia ligand in the second solvation shell indicating for a highly unstable structure of the solvation shell. The obtained structure of the first solvation shell from this simulation is in excellent agreement with experimental data.

Co-Authors Desinta Dwi Ristiana Harno Dwi Pranowo Karna Wijaya Lathifah Puji Hastuti Resi Vita Ginting Triyono Triyono Wahyu Dita Saputri Wega Trisunaryanti Yuniawan Hidayat

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