Performvlookupacrossmultipleexcelsheetsandexportfilepandaspyth

I'm trying to perform vlookup across multiple excel sheets and export the file but I kinda got stuck. Any help is highly appreciated.

Code below:

import pandas as pd

df1 = pd.read_excel('data.xls', sheet_name=None, header = 1)

df2 = pd.read_excel('key.xlsx', sheet_name = 'keys')

writer = pd.ExcelWriter('matched.xlsx')

for sheetname, df in df1.items():                                                                 
    df1.merge(df2,on='year', how = 'left')
    df.to_excel(writer, sheetname, index=False)

writer.save()