You will be shown an abstract from a materials science research paper. Your task is to extract all synthesis operations described in the abstract into a structured JSON format. Your output should be a JSON array. Each entry in the array should be a JSON object describing a single synthesis operation. This object should have the following fields:

- "trigger": A verbal predicate indicating a synthesis operation. This should be a string extracted directly from the abstract.
- "arguments": An array of arguments specifying aspects of the synthesis operation. Each entry in the array should be a length-2 array formatted as [<argument_text>, <argument_type>]. The `argument_text` should be a string extracted directly from the abstract. The `argument_type` should be one of the following types: ["Recipe_Precursor", "Atmospheric_Material", "Participant_Material", "Recipe_Target", "Solvent_Material"].

For instance, suppose an excerpt from the abstract reads:

Tetraethoxysilane (TEOS, 98%) and cetyltrimethylammonium bromide (CTAB, 98%) were purchased from Fluka. The MTTZ-siloxy derivative (triethoxysilyl-propyl-5-mercapto-1-methyl-tetrazole) was synthesized as previously described [38].

This excerpt includes two operations, which could be annotated as follows.

[{"arguments": [["Tetraethoxysilane", "Recipe_Precursor"], ["cetyltrimethylammonium bromide", "Recipe_Precursor"]], "trigger": "purchased"}, {"arguments": [["MTTZ-siloxy derivative", "Recipe_Target"]], "trigger": "synthesized"}]

In your response, please include the JSON and no other text.

Abstract:
10.1039/c3gc41362d
Insights into the stability of gold nanoparticles supported on metal oxides for the base-free oxidation of glucose to gluconic acid
Au was deposited on the metal oxides by the deposition-precipitation method.30 A solution of HAuCl4*3H2O (175 mg) in deionized water (80 mL) was brought to pH 10 by adding a NaOH solution (0.2 M). This solution was mixed with a suspension containing the metal oxide (2 g) in deionized water (25 mL). After stirring for 18 h, the suspension was filtered and washed with an excess amount of deionized water until no more chlorine could be detected by the AgCl test. The supported Au catalyst was dried overnight at 80 degC and then reduced for 4 h at 225 degC in 5% H2 in N2 (100 mL min-1).
The Au/AC catalyst was prepared according to the procedure reported by Biella et al.12 A solution of HAuCl4*3H2O (1 L, 100 μg mL-1) was mixed with 2.5 g of a 2 wt% solution of poly(vinyl alcohol) (PVA, MW ~ 10000). To this solution, 0.1 M NaBH4 solution (20 mL) was added dropwise, leading to the formation of metallic Au NPs. The PVA stabilized Au NPs were then immobilized on activated carbon (Darco(r), 100 mesh) by adding 2 g of the support. The as-synthesized Au/AC catalyst was filtered after 2 h and washed with deionized water.
Nanosized ceria and zirconia, hereafter referred to as nCeO2 and nZrO2, were synthesized according to a previously reported method.30 Briefly, an aqueous solution of Ce(NO3)3*6H2O or ZrO(NO3)2*xH2O (0.8 M, 375 mL) was added to a solution of NH4OH in deionized water (0.8 M, 1.1 L). After stirring for 30 min, the solution was aged at 100 degC for 24 h in a polyethylene vessel. The mixture was cooled down, filtered and washed with an excess amount of deionized water. The resulting particles were dried under vacuum and calcined under an air flow of 100 mL min-1 at 400 degC for 4 h. The other support materials were purchased from Sigma Aldrich and used as received (see ESI+).
[{"arguments": [["metal oxides", "Participant_Material"], ["Au", "Recipe_Target"]], "trigger": "deposited"}, {"arguments": [["HAuCl4*3H2O", "Recipe_Precursor"], ["water", "Solvent_Material"]], "trigger": "brought"}, {"arguments": [["NaOH", "Participant_Material"]], "trigger": "adding"}, {"arguments": [["metal oxide", "Participant_Material"], ["solution", "Participant_Material"], ["water", "Solvent_Material"]], "trigger": "mixed"}, {"arguments": [["suspension", "Participant_Material"]], "trigger": "filtered"}, {"arguments": [["water", "Participant_Material"]], "trigger": "washed"}, {"arguments": [["chlorine", "Participant_Material"]], "trigger": "detected"}, {"arguments": [["N2", "Atmospheric_Material"], ["H2", "Atmospheric_Material"]], "trigger": "reduced"}, {"arguments": [["Au", "Participant_Material"]], "trigger": "dried"}, {"arguments": [["Au/AC", "Recipe_Target"]], "trigger": "prepared"}, {"arguments": [["HAuCl4*3H2O", "Recipe_Precursor"], ["poly(vinyl alcohol)", "Recipe_Precursor"]], "trigger": "mixed"}, {"arguments": [["NaBH4", "Recipe_Precursor"], ["solution", "Participant_Material"]], "trigger": "added"}, {"arguments": [["Au NPs", "Recipe_Target"]], "trigger": "formation"}, {"arguments": [["Au NPs", "Participant_Material"], ["carbon", "Participant_Material"]], "trigger": "immobilized"}, {"arguments": [["support", "Participant_Material"]], "trigger": "adding"}, {"arguments": [["Au/AC", "Participant_Material"]], "trigger": "filtered"}, {"arguments": [["water", "Solvent_Material"]], "trigger": "washed"}, {"arguments": [["nZrO2", "Recipe_Target"], ["nCeO2", "Recipe_Target"]], "trigger": "synthesized"}, {"arguments": [["NH4OH", "Recipe_Precursor"], ["Ce(NO3)3*6H2O", "Recipe_Precursor"], ["ZrO(NO3)2*xH2O", "Recipe_Precursor"], ["water", "Solvent_Material"]], "trigger": "added"}, {"arguments": [["solution", "Participant_Material"]], "trigger": "aged"}, {"arguments": [["mixture", "Participant_Material"]], "trigger": "cooled"}, {"arguments": [["water", "Participant_Material"]], "trigger": "washed"}, {"arguments": [["particles", "Participant_Material"]], "trigger": "dried"}, {"arguments": [["air", "Atmospheric_Material"]], "trigger": "calcined"}, {"arguments": [["materials", "Participant_Material"]], "trigger": "purchased"}]